Computer glossary by asim ali khan

O’ Levels Computer Studies 2014

Prepared & Complied By Asim Ali Khan

Page 1 of 40Author: Asim Ali Khan: Contact: 0333-4316006

TABLE OF CONTENTS

Chapters Contents Page No

One………………… Hardware………………………………………………………………………………….. 2 8‐

Two ……………….. Software…………………………………………………………………………………… 9‐14

Three……………… Organization Of Data………………………………………………………………. 15‐17

Four……………….. Data Integrity…………………………………………………………………………... 18‐19

Five………………… Algorithm Design & Programming Concepts……………………………. 20‐21

Six…..……………… System Development Life Cycle….……………………………………………. 22‐23

Seven….…..……… Commercial &General Data Processing……………………………………. 24‐25

Eight….…..………. Logic Gates & Logic Networks…………………………………………………… 26

Nine……………….. Monitoring & Control……………………………………………………………….. 27‐29

Ten…………………. Data Communication & Network……………………………………………… 30‐35

Eleven…………….. Computer Security System……………………………………………………….. 36

Twelve……………. Social Effects of Information Systems.......................................... 37‐38

Thirteen…………. Employment in the IT Field………………………………………………………. 39


HARDWARE Chapter One

SYSTEM UNIT A system unit is the main body of a desktop computer made up of a metal or plastic enclosure containing the motherboard, power supply, cooling fans, internal disk drives, memory modules,expansion slot, expansion cards, video and network cards and etc.

Example: Desktop Casing. Mini tower Casing, Full tower Casing

MOTHERBOARD –The main board of a computer, usually containing the circuitry for the central processing unit, keyboard, and monitor and often having slots for accepting additional circuitry.

MOUSE –A mouse is a pointing device used to interact with a PC with the help of interactive object (pointer)that controls the movement of the cursor or pointer on a display screen.

Example: Serial mouse, USB mouse, Laser mouse, Optical mouse, Cordless mouse

PARALLEL PORT –A parallel port is a type of interface found on computers for connecting various peripherals

SERIAL PORT –A serial port is a serial communication physical interface through which information transfers in or out one bit at a time to the connected peripheral devices.

USB Port –Universal Serial Bus (USB) is a serial bus standard to interface devices. It was originally designed for personal computers, but it has become commonplace on handheld devices such as portable memory devices, video game consoles, PDAs and portable media players.

CPU –A central processing unit (CPU), or sometimes simply processor, is the component in a digital computer that interprets and executes computer program instructions and processes data.A processor consists of control unit and an arithmetic and logic unit.

ARITHMETIC LOGIC UNIT (ALU) –The section of a microprocessor, which contains a large amount of logic circuitry, and performs the four basic arithmetic functions (addition, subtraction, multiplication, and division

CONTROL UNIT -The control Unit (CU) is a circuitry part of a processor that uses many electrical signals to direct the individual instruction stored in the memory to execute one by one.

REGISTER –Registers are CPU memory which holds data to be processed, the results of calculations, or addresses pointing to the location of desired data; they're of varying number, type, and size depending on the CPU design.

BUFFERS -A buffer is an area of memory used for temporary storage of data when a program or hardware device needs an uninterrupted flow of information. It is found on printers and digital camera where imagedata is held while it awaits processing and transfers to the camera's memory card.


DATA REGISTERS -The memory data register (MDR) is the temporary storage areas for instructions or data found in theCPU. They are not part of memory; rather they are special additional storage locations in CPU.

RANDOM ACCESS MEMORY (RAM) –Volatile semiconductor storage structures that accesses temporary data with a random or direct accessing method erasing, reading and writing memory.

ZIP DRIVE –A Zip drive is a small, portable disk drive used primarily for backing up and archiving personal

computer files.

READ-ONLY MEMORY (ROM) –A semiconductor memory whose data cannot be erased, or overwritten; it can only be accessed (read) The data in a ROM is of a permanent nature and is programmed by the ROM manufacturer.

MEMORY ADDRESS -A memory address is a unique identifier for a memory location at which a CPU or other device can store a piece of data for later retrieval.

ACCUMULATOR -A section of CPU memory, which stores temporary arithmetic information for future processing. The accumulator is interface between the ALU and other sections of the computer.

ADDRESS REGISTER -Keeps track of where a given instruction or a piece of data is stored in memory. Each storage location in the memory is identified by an address which is to be processed or of the next instruction to beexecuted.

STORAGE REGISTER -Temporality holds data taken from the memory or about to be sending to the memory.

GENERAL-PURPOSE REGISTERIt can store both data and addresses, i.e., they are combined Data/Address registers.

INTERFACE CARDS -An interface card is a hardware connector used to link to other devices or computer system for communication.

SYSTEM BUS -The Bus that connects together processor, main memory and Input / Output controllers is called the system bus. A typical system bus contains between 50 and 100 separate lines. Each line is a pathwayfor conveying s single bit.

CONTROL BUS -The Bus is a bi-directional bus, meaning that signals can be carried in both directions. The purpose of the control bus is to transmit command, timing and specific status information between systemcomponents.

DATA BUS -A typical data bus consists of 8, 16, 32 separate lines. It provides a bi-directional path for the movement of data and instructions between components.


ADDRESS BUS -Address bus is the source of fetching data from the memory using address of the data by the processor.

EXAMPLE:

If the address bus consisted of only 8 lines, then the maximum address it could transmitwould be 255.

INTERRUPT –A signal, informing a program that an event has occurred. When a program receives an interrupt signal, it takes a specified action. Interrupt signals can cause a program to suspend itself temporarilyto service the interrupt.

EXAMPLE:The most common types of interrupts are: Program Interrupts, Time Interrupts, Input /

Output Interrupts and hardware failure interrupts.

SYSTEM CLOCK RATE –It is the rate of an electronic pulse used to synchronize processing. Only one action can take place between pulses

CLOCK SPEED –Processors are measured in Mhz (Megahertz) which is an expression of millions, or GHz (Gigahertz) that is thousand millions. A 400 MHz can do 400 million operations a second. A 1.5GHz processor can do 1500 million operations a second.

EXAMPLE:It is measured in megahertz (MHz). 1 MHz = 1 million per second

BUS WIDTH –This is the amount of data the CPU can transmit at a time to the main memory and to input and output devices. Bus width can be 8, 16, 32 or 128.

EXAMPLE:An 8-bit bus moves 8 bits of data at a time.

WORD SIZE –A word size is the amount of data that the CPU can process at a time. An 8-bit processor can manipulate 8 bits at a time.

EXAMPLE:

Processor can be 8, 16, 32 or 64 bit so far.

TRACKBALL –A computer input device for controlling the pointer on a display screen by rotating a ball set inside a case.

EXAMPLE:Trackballs are often seen on laptop computers.

SCANNER –Scanners are used to scan text or pictures into a computer memory.


TOUCH SCREEN –Its an input device that allows user to interact with computer by touching the display screen. Often this uses beams of infrared light that are projected across the screen surface. Interrupting the beams generates an electronic signal identifying the location of the screen. Software interprets the signal and performs the required operation.

LIGHT PEN –A hand-held light-sensitive device used for pointing at characters or objects on a CRT in order to make or modify drawings or to indicate functions to be performed.

SENSOR –A mechanical device sensitive to light, temperature, radiation level, or the like, that transmits a signal to a measuring or control instrument.

BARCODE –Bar code is a set of parallel lines of varying thickness, which are alternately black and white representing a number.

EXAMPLE:Used in super market products and books.

BARCODE READER –A barcode reader is a computer peripheral for reading barcodes printed on various surfaces. Like a flatbed scanner, it generally consists of a light source, a lens and a photo conductor translating optical impulses into electrical ones.

GIGA BYTES –A gigabyte (GB) is a measure of computer data storage capacity and is "roughly" a billion bytes.EXAMPLE:A gigabyte is two to the 30th power, or 1,073,741,824 in decimal notation.

CHECKSUM –A Checksum algorithm is to detect limited and accidental modification such as corruption to stored data or errors in a communication channel. It counts of the number of bits in a transmission unit that is included with the unit so that the receiver can check to see whether the same number of bitsarrived. If the counts match, it's assumed that the complete transmission was received.

MICR –Magnetic Ink Character Recognition is a character recognition system that uses special ink and characters. When a document that contains this ink needs to be read, it passes through a machine, which magnetizes the ink and then translates the magnetic information into characters.

EXAMPLE:

MICR technology is used by banks. Numbers and characters found on the bottom of checks (usually containing the check number, sort number, and account number) are printed using Magnetic Ink. To print Magnetic Ink need, you need a laser printer that accepts MICR toner.

OCRIt is a method of inputting text using a scanner which reflects light from data and writes it on the system digitally.

EXAMPLE:


OMR –Optical Mark Readers are able to sense marks made in right position on a special form. A beam of light is directed on to the surface of the card or document. The beam is reflected from the surface to a light sensor. When a mark passes under the beam less light is reflected back and the presence of the mark is registered.

EXAMPLE:Used for MCQs, questionnaires and enrolment forms

DIGITIZER -A graphics tablet also known as digitizing pad or digitizer is a board which can detect the position of a pen-like stylus on its surface. A design is put on to the board and its shape is traced out with thestylus. Electrical signals sent to the computer record the positions of the stylus.

Example:Reproducing drawings, designs, maps and circuit boards

SMART CARD –A smart card is a plastic made card, which has its own processor and a memory chip. One card can store about 8000 characters.

EXAMPLE:Debit card, Credit cards, Telephone Card

POS – POINT OF SALEPoint-Of-Sale terminal is a device at a point of sale which records details of sales for computer processing.EXAMPLE:

A terminal at a supermarket checkout, with a laser scanner to read bat codes.

DOT-MATRIX PRINTERS -Dot-Matrix printers are impact printers. The paper is held on a cylindrical ‘platen’ with a ribbon held in front of it. Each character is produced by a printing head hitting the ribbon on to the paper. The printing head has in it a rectangular matrix of needles. The appropriate needles are pushed forward electrically to form the shape of the letter required.

INK-JET PRINTERS -An ink-jet printer is a non-impact character printer. They are silent in operation. The print head of an ink-jet printer consists of nozzles 9usually 64). The ink flows through the appropriate nozzle, where itis heated and bubble forms. This expands and breaks, releasing a very small ink droplet.

LASER PRTINERS -These are non-impact printers. A laser beam is used to form an image on a rotating charged drum. Laser printers have toner cartridges, which contain a fine powder called toner. The charged image then picks up the toner particles, which are transferred to the paper, which is also charged. Once theimage has been transferred, heat and pressure are used to stick it to the paper permanently.

COMPUTER OUTPUT ON MICROFICHE (COM) -A microfiche is a rectangular sheet of microfilm large enough to contain a number of pages of data –typically 30 to 300.

EXAMPLE:It is used to store information like the pages of books and newspapers.


GRAPH PLOTTERS -A graph plotter is a device commonly used in producing printing plans, maps, line diagrams and three dimensional drawings on a paper.

VOICE SYNTHESIS -Voice synthesis is used when the output as sound is required.

EXAMPLE:This method is usually useful for handicapped people.

VOICE RECOGNITION -Voice recognition is a technique by which sounds, words or phrases spoken by humans are converted into electrical signals, and these signals are transformed into coding patterns to which meaning has been assigned.

MODEM -A modem allows two computers to communicate over ordinary phone lines. It derives its name from modulate / demodulate, the process by which it converts digital computer data back and forth for use with an analog phone line.

MAGNETIC DISK -A typical magnetic disk has two surfaces or sides, which holds data on circular tracks in which datacan be read and written. Each track is divided into equal section called sectors. The sector in the disks is direct access. A track number and sector number are used as an address to find the data.

MAGNETIC TAPE -

a ribbon of material, usually with a plastic base, coated on one side (single tape) or both sides (double tape) with a substance containing iron oxide, to make it sensitive to impulses from an electromagnet:

EXAMPLE:used to record sound, images, data, etc.

OPTICAL DISKS -

A storage medium from which data is read and to which it is written by lasers. Optical disks can store much more data -- up to 6 gigabytes (6 billion bytes). Digital data is stored, as text, music, or pictures, as tiny pits in the surface and is read or replayed by a laser beam scanning the surface.

PERIPHERAL DEVICES -A peripheral device is any device attached to a computer in order to expand its functionality. Some of the more common peripheral devices are printers, scanners, disk drives, tape drives, microphones,speakers, and cameras.

ROM – Read Only MemoryForm of computer memory that does not lose its contents when the power supply is cut off and that is not rewritable once it is manufactured or written. It is generally employed for programs designed for repeated use without modification, such as the start-up procedures of a personal computer.

PROM – Programmable Read Only Memory –A permanent empty memory chip in which the content is programmed by the users rather than by the chip manufacturer. PROMs are used for storage when their content is not expected to changed


EPROM – Erasable Programmable Read Only Memory -A general term for a non-volatile, semiconductor memory that can be programmed, erased, and reprogrammed many times without damage to the device.

EEPROM – Electronically Erasable Programmable Read Only MemoryElectronically erasable programmable read-only memory. EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge. It holds bits of data code that can be rewritten anderased by an electrical charge, one byte at a time. EEPROM data cannot be selectively rewritten; theentire chip must be erased and rewritten to update its contents.

HARD DISK –A hard disk is a metal plate with magnetic surfaces that stores data on it. The hard drive equipment reads from and writes to the surface of the hard disk.

USB – Universal Serial BusUSB is the most common type of computer por. The USB 1.1 specification supports data transfer rates of up to 12Mb/sec and USB 2.0 has a maximum transfer rate of 480 Mbps. It can be used to connectkeyboards, mice, game controllers, printers, scanners, digital cameras, and removable media drives.

CD-ROM –Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannotaltered or erased.

MP3/MP$ Players –

A digital audio player, or DAP, usually referred to as an MP3 player, is a consumerelectronic device that has the primary function of storing, organizing and playing audio files. SomeDAPs are also referred to as portable media players as they have image-viewing and/or video-playing support.


SOFTWARE

U S ER INT E R F A C E - A user interface allows the user to communicate with the computer.

Chapter Two

COMMAND DRIVEN INTERFACE –A type of computer interface, in which, the input command is a string of text characters. Contrast with graphical user interface.EXAMPLE:

MSDOS, UNIX

GRAPHICAL USER INTERFACE -A graphical user interface lets users interact with their computer via icons and a pointer instead of by typing in text at a command line.EXAMPLE:

Popular GUIs such as Sun Microsystem's OpenWindows Microsoft's Windows and Apple's MacOS

SYSTEM SOFTWARE -System software is a collection of some complex programs, which are assigned to control and operate the computer system. This is usually provided by the manufacturer to control the hardware devices.

EXAMPLE:Operating Systems, Translator programs, Utility programs.

OPERATING SYSTEM -A system software which directs a computer's operations, controlling and scheduling the execution of other programs, and managing storage, input/output, and communication resources.

EXAMPLE:Microsoft Windows, MS-DOS, Linux, UNIX

JOBS OR FUNCTIONS OF OPERATING SYSTEM –1. Job Control

• Job Control – Loads programs into the memory• Provides Continuous process of programs• Provides job queuing facility with a priority system for example in printing process.

2. Memory Management• Stores, retrieves, erases and copied data files and programs.• Support different file organization methods.• Call programs and subroutines into the main memory.

3. Resources keeping management• Number of files and where they are kept.• Availability of remaining storage space on the disk• Keeping logging history on a network• Detecting new hardware

4. Display System Error Messages• Notify the user when an illegal operation is performed.• Display message if less memory is left

5. Maintains security checks• Maintains user’s ID and Password

6. Handles multi-programming• Allow CPU to process more than one program at the same time

7. Controls Input and Output Devices• Transfers data between several peripherals


TRANSLATOR PROGRAM -Translator programs are system software which converts the high-level language instructions

into machine code.

EXAMPLE:Compilers, Interpreters, Assemblers

UTILITY PROGRAMS -The utility program is system software that performs tasks that often are needed and common to all applications.

EXAMPLE:A backup utility program, Defragmenter program, Scandisk program, Copy paste program etc.

APPLICATION SOFTWARE –Application software allows performance of specific tasks, such as writing letters, computing formulas, playing games, or carrying out desktop publishing tasksEXAMPLE:

Word-Processing packages, spreadsheet packages, database Management packages etc.

HIGH-LEVEL LANGUAGE -A high-level language used to write computer programs, as COBOL or BASIC, or, sometimes, an assembly language is used.

LOW-LEVEL LANGAUGE –This is the language that a computer can understand directly. The language consists of binary codes(series of 0’s 1’s).

DESKTOP PUBLISHING –The design and production of publications by means of specialized software enabling a microcomputer to generate typeset-quality text and graphics.

EXAMPLE:MS Publisher, PageMaker, Page Plus

COMMUNICATION SOFTWARE -Communication software - is the program that is used to exchange real-time messages in text, audio and/or video formats for communication purposes from one user ID to another.

EXAMPLE:This term is used when referred to chat and instant messaging programsWindows Net meeting, Microsoft internet browser, Outlook express etc.

WEB BROWSER –A web browser is a software application that enables a user to display and interact with text,images, and other information typically located on a web page at a website on the World Wide Web or a local area network.

EXAMPLE:Explorer, Mozilla, Netscape Navigator stc.

GRAPHIC PACKAGES –These are application software that can be used to create and manipulate images on a computer.EXAMPLE:

Adobe Photoshop, Corel Draw, Paint Brush etc.


COMPUTER AIDED DESIGN (CAD) –This is application software used to display, design and accept any changes to them and calculate and display the result.

EXAMPLE:It assists engineers, architects and other design professionals in their design activities. AutoCAD, Turbo CAD etc.

COMPUTER AIDED DESIGN / COMPUTER AIDED MANUFACTURING – CAD/CAMComputer-Aided Design and Manufacturing. The use of computers in the design and manufacture of products such as cars airplanes ships and computers.

DATA LOGGING PACKAGES –A computer program may automatically record events automatically over a certain period of time. Sensors are used to monitor physical quantities like temperature, pressure, humidity etc.

EXAMPLE:LogIT Lab, Insight 2 etc.

MULTIMEDIA –Multimedia is media that uses multiple forms of information content and information processing (e.g. text, audio, graphics, animation, video, interactivity) to inform or entertain the (user) audience.

EXAMPLE:Encyclopedia, Self-study programs, Games, Presentations etc.

VIRTUAL REALITY –A realistic simulation of an environment, including three-dimensional graphics, by a computer system using interactive software and hardware.

INTEGRATED PACKAGES –There are some application software packages that give some combined facilities of word-processing, spreadsheet, database, desktop publishing and communication software.

EXAMPLE:Microsoft Office, Sun Star Office.

ASSEMBLY LANGUAGE –A programming language that consists of a group of coded letters or labels, called mnemonics. Mnemonic represents a single instruction that is translated into the binary code of machine language.Mnemonics are easier to use than machine language instructions.

For example, the mnemonic "MUL" tells the computer to "MULtiply".

COBOL – Common Business Oriented Language -It is a common language used for programs needed to design business and commercial systems.

FORTRAN – FORmula TRANslator –Developed specifically for engineering and mathematical applications.

COMPILER –A software program that converts (translates) a complete software program written in high-level language SOURCE CODE (such as PASCAL or FORTRAN) into machine language. The entire sourcecode is edited, compiled, and run at one time as compared to an INTERPRETER that is run one line ata time.


INTERPRETER –A high-level language translator that converts individual high-level computer language program instructions (source code) into machine instructions. It translates and executes each statement line-by-line during the running of the program.

ASSEMBLER -A software program that converts (translates) each symbolic instruction written in ASSEMBLY LANGUAGE into the MACHINE LANGUAGE (binary code) of a computer.

INTERRUPT –A signal informing a program that an event has occurred. When a program receives an interrupt signal, it takes a specified action (which can be to ignore the signal). Interrupt signals can cause aprogram to suspend itself temporarily to service the interrupt.

INTERRUPT HANDLER –Also known as a trap handler, an interrupt handler is a software rout i ne performed when an interrupt is received by the computer.

INTERRUPT SOURCE –Interrupt signals can come from a variety of sources. For example, every keystroke generates an interrupt signal. Interrupts can also be generated by other devices, such as a printer, to indicate that some event has occurred. These are called hardware interrupts. Interrupt signals initiated by programs are called software interrupts. A software interrupt is also called a trap or an exception.

INTERRUPT VECTOR –A vector is merely the address of the interrupt handler. When interrupt occurs, the chip automatically jumps to the address stored for that interrupt. There is a table kept in the memory of interrupt vector.An interrupt vector table is a table of interrupt vectors that associates an interrupt handler with aninterrupt request in a machine specific way. A dispatch table is one method of implementing an interrupt vector table.

When the CPU is interrupted by an interrupt, it looks up the interrupt handler in the interrupt vector table, and transfers control to it.

POLLING SYSTEM –A method of repeatedly checking of a device needs to access the communication channel. The main computer checks, or polls, each device on the channel one at a time to see if it has any data to send.

The checking of a part of computer system at intervals.

EXAMPLE:The operating system of a computer may poll the keyboard at intervals while a program is

running. This allows the machine to check if the BREAK KEY of EXCAPE KEY is pressed.

OJECT CODE –The code produced by a compiler or assembler from the source code, usually in the form of machine language that a computer can execute directly, or sometimes in assembly language.Object files contain compact code, often called "binaries"

SOURCE CODE –Source code is what a programmer writes, but it is not directly executable by the computer. It mustbe converted into machine language by compilers, assemblers or interpreters.


BACKUP SOFTWARE –The Backup Software consists of programs for making duplicate copies of date, files such database,mp3/4, digital photos, movies, or anything else on the hard drive or portable device in case of accident or catastrophe.

DISK DEGRAGMENTER / DEFRAGMENATION –Disk Defragmenter is a computer program or a tool that rearranges the data on the hard disk andreunites fragmented files and this technique is commonly known as defragmentation. It improves the overall performance of the computer.

SCANDISK -Scan Disk is a Windows utility used to check hard disk for errors and to correct problems that are found. These errors often occur when Windows locks up and must be restarted.

WORD PROCESSOR -

Word processor is an application software program capable of creating, storing, and printing documents. Unlike the standard typewriter, users using word processors have the ability of creating a document and making any type of changes anywhere in the document. This document can also be saved for modification at a later time or to be opened on any other computer using the same word processor.

SPREADSHEET -

Spreadsheet is a data file made up of rows and columns that are used to sort data and allow a user to manipulate and arrange data easily, commonly numerical data. What makes aspreadsheet software program most unique is its ability to calculate values usingmathematical formulas and the data in the cells.

DATABASE -

A database is a suite of software applications that together make it possible for people or businesses to store, modify, and extract information from a table, group of table or database.

DESKTOP PUBLISHING -

Desktop Publishing software is an application software that produces a high quality document containing text and graphics formatted on a single page. For example desktop publishing is needed for creating such printed material as book covers, brochure, fliers, etc.

COMMUNICATION SOFTWARE -

Communication software is used to provide remote access to systems and exchange files and messages in text, audio and/or video formats between different computers or user IDs. This includes terminal emulators, file transfer programs, chat and instant messaging programs

COMPUTER AIDED DESIGN SOFTWARE - CAD

The use of computer programs and systems to design detailed two- or three-dimensional models of physical objects, such as mechanical parts, buildings, and molecules.


INTEGRATED SOFTWARE -

A collection of computer programs designed to work together to handle an application, either by passing data from one to another or as components of a single system. A collection of computer programs that work as a unit with a unified command structure to handle several applications, such as word processing, spread sheets, data-base management, graphics, and data communications.

PRESENTATION SOFTWARE -

A presentation program is a computer software package used to display information, normally in the form of a slide show. It typically includes three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images and a slide-show system to display the content.


ORGANIZATION OF DATA Chapter Three

ALPHANUMERIC –alphanumeric are comprised by the combined set of the 26 alphabetic characters, A to Z, and the 10Arabic numerals, 0 to 9. In some usages, the alphanumeric character set may include both upper and lower case letters, punctuation marks, and symbols (such as @, &, and *, for example).

FIELD –A field is a column or data item which gives the same information of a same data type for all the records.EXAMPLE:

Employee ID: Emp-099

RECORD –A record is a collection of many related fields.

FILE –A file is a collection of many related records.

DATABASE-A collection of similar information stored in a file, such as a database of addresses. This information may be created and stored in a database management system (DBMS).

DATA-BASE MANAGEMENT SYSTEM (DBMS) –A software program that controls and supervises the updating, editing, and execution of items from multiple files in a data base environment.

RELATIONAL DATABASE –A relational database is a set of tables containing data fitted into predefined categories. Each table (which is sometimes called a relation) contains one or more data categories in columns. Each row contains a unique instance of data for the categories defined by the columns.

EXAMPLE:a typical business order entry database would include a table that described a customer with columns for name, address, phone number, and so forth. Another table would describe an order: product,customer, date, sales price, and so forth.

PRIMARY KEY –Primary key is a field that is unique to a particular record.

EXAMPLE:InvoiceNo is a primary key

FOREIGN KEY –A foreign key is a column or combination of columns that is used to establish and enforce a link between the data in two tables duplicating primary key on the base table to link table.

ARRAY

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Author: Asim Ali Khan: Contact: 0333-4316006

An array, also known as a vector or list, is one of the simplest data structures in computer programming. Arrys hold a fixed number of equally-sized data elements, generally of the same data type.

Example:ComputerMarks[1] = 75

FILE ORGANIZATION –The method by which the records are organized in a file is called file organization.

SERIAL FILE ORGANIZATION –In serial file organization method, each record is stored one after another with no logical order. Records are just added at the EOF(End Of File)

SEQUENTIAL FILE ORGANIZATION –The records in this file organization method are stored one after the other in a logical order. It will usually be in ascending order of the primary key.

INDEXED SEQUENTIAL FILE ORGANIZATION –The indexed sequential file has its own index. The index contains entries consisting of the key to each record stored on the file and the corresponding disk address for that record.

DIRECT ACCESS FILE –In direct access method, it allows the record pointer to go directly to the desired record. It is the ability to access any given record instantly that has made computer system convenient.

MASTER FILE –A permanent file, periodically updated, that serves as a reliable source of data.

EXAMPLE:Employee detail master file, book detail master file etc.

TRANSACTION FILE –Transaction flies contain data that record events. Records in a transaction file are placed in time order and are processed by a computer to update related master file records.

EXAMPLE:In business, transactions are placing an order, updating the stock, making a payment etc.

BACK FILES –Backup copies of files are kept in case the original file is damaged or lost and cannot be used. Back should be kept in diskettes or magnetic tape with regular intervals

ARCHIVING –Archiving is the process of backing up data so that it is not lost in the case of a hard disk failure. Files have an archive attribute that is removed when a file has been backed up and then replaced when afile has been changed.

SORTING –Sorting is any process of arranging items in some sequence and/or in different sets, and accordingly

MERGING –It is a technique to combine two separate sets of data into one set. The resulting data may be in their original order or re-sequenced by key field or some other attribute of the data.

FILE GENERATIONS -

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It is a backup file system of proven reliability in which files are kept in three copies. The father, son and grandfather files. The son file is the most recent copy. After the son file has been in use for some time, a new recording will be made. This will be new son file, and the old son file will be renames as father, and the old father file becomes grand father. This scheme ensures file backup and can be easily maintained.

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DATA INTEGRITY Chapter Four

TRANSCRIPTION ERROR –

This error occurs when the source document is misread or mistyped. The usual method of data capture is key-to-disk sot that many errors can occur. Bad handwriting can also be confusing for the data entry operator.

EXAMPLE:Employee ID S550 can be entered as 5SS0

TRANSPOSITION ERROR –Transposition error occurs when two digits or letters are swapped around. It happens when typing the data in high speed.

EXAMPLE:Year of data of birth 1998 can be entered 1989 by mistake.

VALIDATION –Validation checks are made on data to make sure that the data is accepted or valid. The computer program does the validation and the user is notified through a screen message if any unusual data hasbeen entered.

TYPE CHECK –This check make sure that the right data type has been entered. Such data type of checks can detect numbers where characters should have been entered and vice versa.

RANGE CHECK –Range checks are performed on numbers and date to make sure that they lie within a specified range.

LENGTH CHECK –A certain specific length is required, that contains a fixed number of characters which cannot be exceeded.

PRESENCE CHECK –Entering data into a database the presence of some fields may be compulsory. Since, they cannot be left blank.

HASH TOTAL –Hash totals are the totals of a specific set of numbers that have been entered into the computer. It is meaningless total.

CONTROL CHECK –A Control total is like a hash total except that the total has some meanings.

CHECK DIGIT –A decimal (or alphanumeric) digit added to a number for the purpose of detecting the sorts of errors humans typically make on data entry.

LOOKUP TABLES –Lookup tables are used to make sure that the data entered is actually identified with the original list of code already stored in the computer.

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PARITY ERROR –a method for detecting errors in data communications or within a computer system by counting the number of ones or zeros per byte or per word, including a special check bit, to see if the value is evenor odd.A bit added to a binary code that indicates parity and is used to check the integrity of data.

VERIFICATION –Data verification involves checking what is in the input document (source document / Original document) to see if it is exactly the same as what is entered into the computer.

PROOF READING –Proof reading involves carefully checking what has been typed in the computer by using print out and compare with the original document.

DOUBLE ENTRY METHOD (Key-to-disk-systems) –Double entry method is involves two people typing in the same data and only if the data is identical will it be accepted for further processing.

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ALGORITHM DESIGN & PROGRAMMING CONCEPTS Chapter Five

ALGORITHM –An algorithm is a series of instructions or steps for the solution of a specific problem.

TOP DOWN DESIGN –A hardware and/or software design approach that starts at the most general level of a machine or software program. It proceeds, step-by-step, to lower levels, adding detail as the design progresses.

PROGRAM FLOWCHART –A flowchart is a pictorial presentation of an algorithm or a process.

SEQUENCE CONTROL STRUCTURE –The sequence control structure is the most straightforward. One statement simply follows another in sequence.

SELECTION CONTROL STRUCTURE –The selection control structure is used to make logical decisions.

REPETITIVE / ITERATIVE CONTROL STRUCTURE –The repetition or Iterative control structure is a looping mechanism.

PSEUDOCODES –A pseudo-code is an English-like non-standard language that lets you state your solution with more precision. A pseudo-code is useful for writing instructions in plain English before they are translatedinto a programming language.

MODULAR PROGRAMMING –Breaking a program down into smaller tasks most readily solves complicated problems. These smaller unites can be called modules. Each module performs a specific function. The modules can be together when required.

COMPILATION ERROR –Compilation error refers to a state when a compiler fails to compile a piece of computer program source code, either due to errors from the compiler itself, or more likely syntax errors in the code. Acompilation error message often helps programmers debugging the source code for possible syntax errors.

LOOP –A loop is a sequence of statements which is specified once but which may be carried out several times in succession. The code "inside" the loop is obeyed a specified number of times, or once for each of acollection of items, or until some condition is met.

SYNTAX ERROR –Errors that occur, when the syntax of the program or the rules defining the legal sequence of the symbolic elements, in a language are not correct.

SEMENTIC ERROR –Semantic errors are caused by wrong application of the language.

LINKING ERRORS -These errors occur when the source program has not been linked correctly with a library routine, external file or database.

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RUN TIME ERRORS –These errors occur while the program is being run.

SYSTEM FAILURE ERROR–These errors occur when the program stops abruptly, mid way due to no specific fault of the user.

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SYSTEM DEVELOPMENT LIFE CYCLE Chapter Six

STEPS INVOLVES IN SYSTEM DEVELOPMENT LIFE CYCLE –1. System Analysis2. System Design3. System Testing4. System Documentation5. System Implementation6. System Maintenance

SYSTEM ANALYIST GO TRHOUGH THE FOLLOWING PROCESSES -

• Fact finding• Investigation and problem definition• Conduct a feasibility study• Prepare a feasibility report

FOUR WAYS OF FACT FINDINGS IN ANALYSIS PHASE -

INTERVIEWING –Interviewing people by asking questions from the senior manages, middle managers, operational managers and other staff about their routine work and problems.

QUESTIONNAIRES –a list of questions, usually printed, submitted for replies that can be analyzed for usable information.

OBSERVATION –Observation is an activity to noticing the staff at their work.

INSPECTION –Examining all type of documents, screen displays, and files, those are being used in present system.

FEASIBILITY STUDY –A feasibility study is a preliminary study undertaken to decide and document a project's possibility. The results of this study are used to make a decision whether to proceed with the project, or chart it. It is mainly consist of a cost/benefit analysis.

FEASIBILITY REPORT –The feasibility report is a written report given to the director of the company and is really a summary of the results of the feasibility study.

DATA STORAGE METHODS -1. Decide on the number of files (tables) and fields in each table.2. Decide on the data type and length of each field3. Decide on the key fields of each table4. Decide on the properties of each field5. Draw the relationship between the tables.

DIRECT IMPLEMENTATION –In this method, on a pre-decided date the users start using the system. This method is only used for small computer systems.

PHASED IMPLEMENTATION –Each job is introduced separately in this method, rather than all jobs being introduced together.

PARALLEL IMPLEMENTATION –In parallel running, the new system is run alongside the existing system. For some reason if the new system fails to work as expected, then we still have the chance to use the precious system.

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TECHNICAL DOCUMENTATIONDocumentation for a programmer or system analyst needed when a system is being up graded or improved including program flowchart test plans data structure, software requirements, hardwarerequirements.

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COMMERCIAL & GENERAL DATA PROCESSING Chapter Seven

REAL TIME PROCESSING –In real time processing, the system is automatically updated immediately when transactions occur.

EXAMPLE:Traffic light system, ATM etc.

BATCH PROCESSING –a form of data processing in which a number of input jobs are grouped for processing during the same machine run. The jobs / transactions are collected and then processed in one go rather than in anumber of parts.

EXAMPLE:Utility Bills, Pay slips etc.

TRANSACTION PROCESSING –This processing is only undertaken when needed for a special situation and not in set time intervals.

EXAMPLE:Sales invoices

MULTITASKING –The technique of using several applications programs (tasks) in a computer system or on several terminals in a network at the same time. Multitasking can simultaneously work with several programsor interrelated tasks that share memories, codes, buffers, and files.

MULTIUSER –The term describes the capability of a computer system to be operated at more than one terminal at the same time.

EXPERT SYSTEM –An expert system, also known as a knowledge based system, is a computer program that contains some of the subject-specific knowledge of one or more human experts.

An expert system is a computer system or program that uses artificial intelligence techniques to solve problems that ordinarily require a knowledgeable human.

EXAMPLE:Used in Medical diagnosis system, Flight simulation etc.

COMPUTER MODELLONG –A computer simulation or a computer model is a computer program that attempts to simulate an abstract model of a particular system.

EXAMPLE:Computer simulations have become a useful part of mathematical modelling of many natural

systems in physics (Computational Physics), chemistry and biology, human systems in economics,psychology, and social science and in the process of engineering new technology, to gain insight intothe operation of those systems.

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MATHEMATICAL MODELS –A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system.

EXAMPLE:Mathematical models are used particularly in the natural sciences and engineering disciplines

(such as physics, biology, and electrical engineering) but also in the social sciences (such as economics, sociology and political science); physicists, engineers, computer scientists, and economists use mathematical models most extensively.

SIMULATION MODELING –Simulation software can be used in simulation modeling. A full-scale flight simulator of the type used to train pilots provides graphics display of what is visible from the plane.

ARTIFICIAL INTELLIGENCEThis is the area of computer science, focusing on creating machines that can engage on behaviors that humans consider intelligent. The ability to create intelligent machines, creating systems which canmimic human thought, understand speech, beat the best human chess player, and countless otherfeats never before possible.

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LOGIC GATES Chapter Eight

LOGIC GATE –A device, usually an electrical circuit, that performs one or more logical operations on one or more input signals. Logic gates are the building blocks of digital technology.

Example: AND, NAND, OR, NOR etc.

TRUTH TABLE –A table listing the truth-values of a proposition that result from all the possible combinations of the truth-values of its components.

ELECTRONIC CIRUIT –An electronic circuit connects active and passive electronic components suchas resistors, capacitors, microprocessors, transistors or vacuum tubes. The electronic circuits are typically built using a printed circuit board (PCB) that is used to mechanically support and electricallyconnect electronic components.

DIGITAL CIRUIT –Digital electronics are electronics systems that use digital signals. Digital electronics are representations of Boolean algebra and are used in computers, mobile phones, and other consumerproducts

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MONITORING & CONTROL Chapter Nine

ANALOG COMPUTERAnalog computers represents the data as continuous measurement of physical property such as

Example: voltage, pressure, speed as opposed to counting discrete signals.

ADC (Analog-to-Digital Converter) -ADC is a device that converts the continuous analog signal to a multi-level digital signal without altering its content.

EXAMPLE:Used to retrieve data using sensors

ANALOG SIGNALS -Variety of signals and wavelengths that can be transmitted over communications lines such as the sound of a voice over the phone line.

DIGITAL DATA -Is discrete data which is understood by a computer in a form of binary numbers (0’s and 1’s).Digital signals have distinct pulses. They are either ON or OFF. Computer transmits this sort of signals.

DATA-LOGGING -It is the collection of data automatically over a certain period of time

EXAMPLE:

Weather forecasting, Rainfalls etc.

REMOTE SENSING -Remote sensing is a technique used to gather information (size, color, location, temperature, smoking) about an object or an area without actually touching it.

EXAMPLE:Temperature sensor used in Air-condition

FEEDBACK LOOP -Digital computer receives the signal from the sensor and respond accordingly in a recurring process manner. Therefore this process is called feedback loop.

EXAMPLE:Computer, Temperature sensor and ADC

SENSOR –This is a mechanical device sensitive to light, temperature, radiation level, or the like, that transmits a signal to a measuring or control instrument.

EXAMPLE:Motion sensor, Temperature sensor, Heat Sensor, Light Sensor etc.

MOTION SENSOR –Unlike most sensors, these are digital switches that record a time when triggered with a moving object such as human being or a vehicle.

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PRESSURE SENSOR –Pressure sensor can sense air pressure, arterial blood pressure and some are sensitive enough to monitor the respiration of mealworms and changes in osmotic pressure. They can also be used aspressure pads to be used in a computer controlled traffic light system.

pH SENSOR –A versatile sensor used in conjunction with a pH electrode. It makes acid base titration curves easy and there are biological applications in monitoring respiration, photosynthesis or fermentation.

GAS SENSOR –A gas sensor is an analog device which detects the presence of various gases within an area, usually as part of a safety system. This type of sensor is used to detect a gas leak and interface with a controlsystem so a process can be automatically shut down.

SOUND SENSOR –The sound level is sensed through this sensor. These sensors can be used to record the level od sound coming from the bees, birds or other animals.

HUMIDITY SENSOR –The air or soil is filled with moisture and this sensor is used to determine the amount of moinsture present.

POSITION SENSOR –The angle of a spindle can be sensed automatically using a position sensor. When robots are used this sensor could be used, to feed back the robot position.

ACTUATORS –Actuators are a kind of motors. This hardware device reacts according to signals given to them by computers. An actuator motor would be used to open a latch in a heated room then it gets too hot.

STEPPER MOTOR –A stepper motor works in a series of small steps. Stepper motors generally look bigger than ordinary motors and have several wires coming out of them. The rotator can be turned through several angles.Pulses sent from the computer instruct the motor to turn through the required angle.

QUALITY CONTROL –An example of quality control can be seen in the manufacture of paper. The thickness of paper during its manufacture is monitored. Process control is important for quality control.

AIRCRAFT RADAR –Radar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weatherformations, and terrain.

ROBOT –A stand-alone hybrid computer system that performs physical and computational activities. Capable of performing many different tasks, it is a multiple-motion device with one or more arms and joints.

ARTIFICIAL INTELLIGENCE -This is the area of computer science, focusing on creating machines that can engage on behaviors that humans consider intelligent. The ability to create intelligent machines, creating systems which can mimic human thought, understand speech, beat the best human chess player, and countless other feats never before possible.

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APPLICATION:Robots are designed for many purposes. In manufacturing, they are used for welding, riveting,

scraping and painting. They are also deployed for demolition, fire and bomb fighting, nuclear siteinspection, industrial cleaning, laboratory use, medical surgery (see telepresence surgery),agriculture, forestry, office mail delivery as well as a myriad of other tasks. Increasingly, moreartificial intelligence is being added. For example, some robots can identify objects in a pile, select the objects in the appropriate sequence and assemble them into a unit.

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DATA COMMUNICATION & NETWORK Chapter Ten

VIDEOCONFERENCING –A videoconference is a live connection between people in separate locations for the purpose of communication, usually involving audio and often text as well as video.

SIMPLEX –A data transmission mode that provides transmission in one direction only.

EXAMPLE:Radio, TV etc.

HALF-DUPLEX –A communications mode that allows transmission and reception of digital data between computers, but not simultaneously.

EXAMPLE:ATM Machine, Walky talky

FULL DUPLEX –A data transmission mode that provides simultaneous and independent transmission and reception. Aconventional telephone communication is an example of this technique.

EXAMPLE:Telephones

TWISTED PAIR -Twisted pair cabling is a form of wiring in which two conductors are wound together for the purposes of canceling out electromagnetic interference (EMI) from external sources and crosstalk fromneighboring wires.

COAXIAL CABLE –Coaxial cable is an electrical cable consisting of a round conducting wire, surrounded by an insulating spacer, surrounded by a cylindrical conducting sheath, usually surrounded by a final insulating layer (jacket).

OPTICAL FIBER -Fiber optics (optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over longdistances.

EXAMPLE:They are used in medical imaging, mechanical engineering inspection and communication system.

OPTICAL SWITCHIn telecommunication, an optical switch is a switch that enables signals in optical fibers or integrated optical circuits (IOCs) to be selectively switched from one circuit to another.

WAVES -A wave is a disturbance that propagates through space or spacetime, often transferring energy

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INFRARED -A light that is so red that it is not viewable to the naked eye. It uses this invisible beam of light to transmit a pre-programmed 'line-of-sight' signal to certain electronic components. Its typical useinvolves wireless devices such as a TV remote controller.

RADIO WAVE -Radio waves are of electromagnetic wave occurring radio frequency portion of the electromagnetic spectrum. A common use by humans is to transport information through the atmosphere or outer space without wires.

MICROWAVE -Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz)frequencies, but relatively short for radio waves. Microwaves have wavelengths approximately in the range of 30 cm (frequency = 1 GHz) to 1 mm (300 GHz).

SATELLITE TRANSMISSION -an artificial earth satellite that facilitates communications, as radio, television, and telephone transmissions, by means of the reflection or the amplification and retransmission of signals between stations on earth or in space.

NETWORKS –A system containing any combination of computers, computer terminals, printers, audio or visual display devices, or telephones interconnected by telecommunication equipment or cables: used totransmit or receive information.

LOCAL AREA NETWORK –A system for linking a number of microcomputers, terminals, work stations, etc. with each other or with a mainframe computer in order to share data, printers, information, programs, disks, etc.; usually confined to one office or building.

WIDE AREA NETWORK –A computer network that spans a relatively large geographical area.

INTERNET –An international conglomeration of interconnected computer networks. Begun in the late 1960s, it wasdeveloped in the 1970s to allow government and university researchers to share information. The Internet is not controlled by any single group or organization. Its original focus was research and communications, but it continues to expand, offering a wide array of resources for business and home users.

INTRANET –A network of networks is called Internet.

EXTRANET –An extranet is a private network that uses Internet protocols, network connectivity, and possibly the public telecommunication system to securely share part of an organization's information or operationswith suppliers, vendors, partners, customers or other businesses.

GATEWAY –software or hardware that links two computer networks.

SERVER -A computer system in a network shared by multiple users. Examples include mail, database, fax, web, print, terminal, and video server systems. Typically servers run the specialized Network Operating Systems (NOS) which control network resources.

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FILE SERVER –A computer that makes files available to workstations on a network.

WEB SERVER –A computer that is responsible for accepting HTTP requests from clients, which are known as Web browsers, and serving them HTTP responses along with optional data contents, which usually are Webpages such as HTML documents and linked objects (images, etc.).

PRINT SERVER –A print server, or printer server, is a computer or device to which one or more printers are connected, which can accept print jobs from external client computers connected to the print serverover a network. The print server then sends the data to the appropriate printer that it manages.

MODEM –modem [modulator/demodulator], an external device or internal electronic circuitry used to transmit and receive digital data over a communications line normally used for analog signals. A modemattached to a computer converts digital data to an analog signal that it uses to modulate a carrierfrequency.

HUB or SWITCHAn Ethernet hub or concentrator is a device for connecting multiple twisted pair or fiber opticEthernet devices together, making them act as a single piece or segment.

MULTIPLEXING –A multiplexing is a method that encodes or multiplexes information from two or more data sources into a single channel.

MULTIPLEXER –A multiplexer or mux is a device that selects one of many data-sources and outputs that source into a single channel.

EXAMPLE:example would be using a multiplexer to allow 10 computers to attach where only one could

get the transmission.

STAR TOPOLOGY –A star network consists of one central switch, hub or computer which acts as a medium to transmit messages.

RING TOPOLOGY –A ring network is a network topology where each node is connected to two other nodes, so as to create a ring. Ring networks tend to be inefficient when compared to Star networks because datamust travel through more points before reaching its destination.

BUS TOPOLOGY –an arrangement of computers on a local-area network in which each computer is connected to a central cable through which data is channeled.

IP (INTERNET PROTOCOL) ADDRESS -An Internet Protocol address is a unique set of numbers used to locate another computer on a network. The format of an IP address is a 32-bit string of four numbers separated by periods. Each number can be from 0 to 255 (i.e., 1.154.10.266).

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NEWSGROUPS –a discussion group on a specific topic, maintained on a computer network.

WWW –The World Wide Web is a system of interlinked, hypertext documents that runs over the Internet. With a Web browser, a user views Web pages that may contain text, images, and other multimediaand navigates between them using hyperlinks.

ELECTRONIC MAIL –Electronic mail generally called 'e-mail' messages from one individual to another sent via telecommunications links between computers or terminals. This is a store and forward method ofcomposing, sending, storing, and receiving messages over electronic communication systems.

SEARCH ENGINES –search engine is technically the software and algorithms used to perform a search, the term has become synonymous with the Web site itself. For example, Google is a major search site on the Web,but rather than being called the "Google search site," it is commonly known as the "Google searchengine

EXAMPLE:Some popular search engines are Alta Vista, Google, HotBot, Yahoo!, Web Crawler, and Lycos.

REMOTE LOGIN –Remote login refers to any method of controlling a computer from a remote location.Software allows to use the distant computer when it is difficult or impractical to be physically near a system in order to use it.

PROTOCOL –A protocol is a rule or standard that controls or enables the connection, communication, and data transfer between two computing endpoints.

FTP –File Transfer Protocol. A format and set of rules for transferring files from a host to a remotecomputer.

HTML -Hypertext Markup Language. A standard of text markup conventions used for documents on the WorldWide We b . Browsers interpret the codes to give the text structure and formatting (such as bold, blue, or italic).HTTP –Hypertext Transfer Protocol. A common system used to request and send HTML documents on theWorld Wide Web. It is the first portion of all URL addresses on the World Wide Web

EXAMPLE:http://www.cie.org

TCP (Transmission Control Protocol) –A connection-oriented protocol that transmits data in byte streams. Data is transmitted in packets called TCP segments, which contain TCP headers and data. TCP is a “reliable? Protocol because it usescheck-sums to verify data integrity and hand-shaking to make sure transmitted data is received intact.

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TCP/IP (Transmission Control Protocol/Internet Protocol) –This communications protocol is used for data exchange between diverse computer hardware and operating systems

HYPERLINK –Text or an image that is connected by h ypertext coding to a different location. By selecting the text or image with a mouse, the computer “jumps to” (or displays) the linked text.

HANDSHAKING –Exchange of signals between two devices or nodes to establish communication is called handshaking.

EXAMPLE:Computer and Printer

ISP –An organization which provides access to the Internet typically for a fee. All major metropolitan areas in the world have numerous individual ISPs which will provide Internet service.

BANDWIDTH –Bandwidth is a amount of data transferred from ISP to the user within the specified time period.

DIAL-UP CONNECTION -Dial-up Internet connection is a form of Internet access that uses telephone lines. The user's computer or router uses an attached modem connected to a telephone line to dial into an Internetservice provider's (ISP) node to establish a modem-to-modem link, which is then used to route Internet Protocol packets between the user's equipment and hosts.

BROADBAND -This refers to high-speed data transmission in which a single cable can carry a large amount of data at once. The most common types of Internet broadband connections are cable modems (which use the same connection as cable TV) and DSL modems (which use your existing phone line).

WAP –WAP is an open international standard for applications that use wireless communication. Its principal application is to enable access to the Internet from a mobile phone or PDA.

WiFi –Short for "Wireless Fidelity, or High Fidelity, which refers to high-quality audio or surround sound. Wi- Fi refers to wireless network components that are based on one of the Wi-Fi Alliance's 802.11standards.

URL (Uniform Resource Locator) –A Uniform Resource Locator, URL, or Web address, is a standardized address for some resource (such as a document or image) on the Internet (or elsewhere).

UPLOAD -The process of transferring information from a computer to a web site (or other remote location on a network). To transfer information from a computer to a web site (or other remote location on anetwork).

Telecommuting –Telecommuting is working from a remote location using computers, telephones, facsimile machines, and other remote capabilities, rather than commuting via automobile or other mode of transportations.

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Benefits of Telecommuting:

• Conserving Energy• Preserving the Environment• Improving Worker and Public Safety, and• Enhancing Family Values

TELECONFERENCING -Teleconference is the live exchange of information among persons and machines remote from one another but linked by a telecommunications system. A remote “face-to-face c h at ,” when two or morepeople using a webcam and an Internet telephone connection chat online. The webcam enables both live voice and video.

VIDEO CONFERENCING –Video conferencing is a communications technology that integrates video and voice to connect remote users with each other as if they were in the same room. Each user needs a computer, webcam,microphone, and broadband internet connection for participation in video conferencing. Users see and hear each other in realtime, allowing natural conversations not possible with voice-only communications technology.

WORKSTATION –The work area and/or equipment used for computer operations, including computer-aided design(CAD). The equipment generally consists of a monitor, keyboard, printer and/or plotter, and other output devices.

BLUETOOTH -Radio technology that connects electronic devices without using a cable. Data and voice can be exchanged at ranges of up to 10 meters without the need for devices to be lined up together

FAX -Also known as a facsimile, telecopying, or telefacsimile, a fax is a transmission of graphics and/or text over the phone line.

NODE –In networks, a processing location. A node can be a computer or some other device, such as a printer. Every node has a unique network address, sometimes called a Data Link Control (DLC) address orMedia Access Control (MAC) address.

ROUTER –A computer or network device which transfers packets of data from one network to another.

DOWNLOAD –

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COMPUTER SYSTEM SECURITY Chapter Eleven

VIRUS –Computer virus is a small software programs that is designed to spread from one computer to anothercorrupt or delete data on the hard-disk. Viruses are most easily spread by attachments in e-mail messages or instant messaging messages.

ANTI-VIRUS –Antivirus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software

PASSWORD –a word or other string of characters, sometimes kept secret or confidential, that must be supplied by a user in order to gain full or partial access to a multiuser computer system or its data resources.

HACKING –Un-authorize access of data in any computer using different communication media illegally is calledHacking.

SOFTWARE COPYRIGHT –Copyright is a mechanism to prevent the unauthorized copying of the software. It is a legal term that refers to the author of an original piece of work being the sole owner of that work, which gives that person the right to re-publish or alter that work however they like.

ENCRYPTION –The process of transmitting scrambled data so that only authorized recipients can unscramble it. Forinstance, encryption is used to scramble credit card information when purchases are made over theInternet.

BACKUPS –

1. The term Backup means to copy files to another medium such as a flash drive, a disk drive or tape drive as a precaution in case the first medium such as hard disk fails. Files should always be backedup regularly as even the most reliable computer can break down eventually. Files are backed up using operating system commands or with a backup software utility program. The Backup program willusually compress the data so that backup itself requires less space.

2. Backup is the process of copying files or databases so that they will be saved in a secondary storage device such as hard disk, floppy disk or tape backup in case of loss of data due to computer failure or other disasters.

FIREWALL -A set of security programs that protect a computer from outside interference or access via theInternet. Firewalls can either be hardware and/or software based.

ELECTRONIC SCABBINGAdapted from the slang term scab (a strike-breaker or one who crosses a strike line to work in place of striking employees), electronic scabbing refers to the practice used by managers and otherexecutives when computer networks are used to transfer electronic documents (e.g., accounting,clerical, word processing, databases, records) to a non-striking workforce

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THE SOCIAL EFFECTS OF INFORMATION SYSTEMS Chapter Twelve

DATA PROTECTION ACT –The Data Protection Act (DPA) is a United Kingdom Act of Parliament that provides a legal basis and allowing for the privacy and protection of data of individuals in the UK.

THE PRINCIPLES OF DATA PROTECTION ACT -

1. Personal data shall be processed fairly and lawfully and, in particular, shall not be processed unless-

2. at least one of the conditions in Schedule 2 is met, and3. in the case of sensitive personal data, at least one of the conditions in Schedule 3 is also met.4. Personal data shall be obtained only for one or more specified and lawful purposes, and shall

not be further processed in any manner incompatible with that purpose or those purposes.5. Personal data shall be adequate, relevant and not excessive in relation to the purpose or

purposes for which they are processed.6. Personal data shall be accurate and, where necessary, kept up to date.7. Personal data processed for any purpose or purposes shall not be kept for longer than is

necessary for that purpose or those purposes.8. Personal data shall be processed in accordance with the rights of data subjects under this Act.9. Appropriate technical and organisational measures shall be taken against unauthorised or

unlawful processing of personal data and against accidental loss or destruction of, or damageto, personal data.

10. Personal data shall not be transferred to a country or territory outside the European EconomicArea unless that country or territory ensures an adequate level of protection for the rights and freedoms of data subjects in relation to the processing of personal data.

ENVIRONMENTAL ISSUES –• Reduce Energy Consumption

Computers are capable of handling and controlling many systems used in office and factories. For example, the computer can control the heating system used in a factory.It will heat only the used rooms saving a huge amount of energy.

• Reduce WastageThis is mainly used in industrial process where the computer controls most of the processing that takes place. This helps accurate work and reduce the wastage.

• Reducing Car Pollution.With the introduction of networks people tend to work at home rather than going to an office (Tele-Commuting). This reduces fuel consumption and car pollution.

ETHICAL, MORAL AND SOCIAL ISSUES

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• Software TheftMany people have software in their hard disks, which has not been purchased bythem. According to the Designs and Patents Act it is a criminal offence to copy or steal software.

• HackingThis means gaining illegal access to someone else’s computer system.

• PrivacyThough there is a Data Protection Act most of the people are unaware of it. Because of the network systems the concept of data privacy is lost.

• Job LossesWith the new systems and software less people are required in the offices. Computers replace humans, making more people unemployed.

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EMPLOYEMENT IN THE IT FIELD Chapter Thirteen

SYSTEM ANALYST –The person responsible for the development of an information system. Systems analysts design and modify systems by turning user requirements into a set of functional specifications, which are theblueprint of the system.

SOFTWARE ENGINEER –A person who designs and programs system-level software, such as operating systems, database management systems (DBMSs) and embedded systems.

WEB DESIGNER –A person who creates a Web site. Web designers may use Web authoring software or an HTML editor to create the actual pages, or they may design the overall look and let a Webmaster do the actual coding.

SYSTEM MANAGER –The person who manages computer systems in an enterprise, which may include any and all of the following functions: software distribution and upgrading, user profile management, version control,backup & recovery, printer spooling, job scheduling, virus protection and performance and capacityplanning.

DATA PROCESSING MANAGER –The Data Processing Manager is responsible for the scheduling and operation of mainframe computer processing production to provide efficient, effective, and timely service to the Bank.The position of Data Processing Manager directs the technical support efforts which includes responsibility for all related computer system software, hardware, and database administration

SOFTWARE PROGRAMMER –A programmer or software developer is someone who programs computers, that is, one who writes computer software. The term computer programmer can refer to a specialist in one area of computerprogramming or writes code for many kinds of software.

Education

Computer glossary by asim ali khan