UNIT: II I. COMPUTER SOFTWARE The term software refers to set of computer programs, procedures and associated programs, documents describing the programs and how they are used.A software package is a group of programs that solve a specific problem or performs a specific type of job eg: a word processing package may contain programs for text editing, formatting, drawings, graphics,etc. hence,a multipurpose computer syatem has a several software package one each foe each type of job it can perform.

APPLICATION & SYSTEM SOFTWARESoftware refers to a collection of programmes & associated documents. There are two types of software:-

o System Software : It is a set of 1 or more programs, which controls the operation &/or extends the processing capability of a computer system. It makes the operation of a computer system more effective & efficient. It helps hardware components work together & provide support for the development & execution of application software (programs).Good system software enables development & execution of application packages on a computer system with less time & efforts. A computer without some kind of system would be very ineffective & most likely impossible to operate. Programs included in a system software package are called system programs & programmers who prepare system software are referred as system programmer.

o Application Software : It is a set of 1 or more programs, which solves a specific problem, or does a specific task. Programs included in an application software package are called application programs & programmers who prepare system software are referred as application programmer.

1. PROGRAMMING LANGUAGES AND THEIR SOFTWARE

A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely.

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o Object-Oriented Programming Languages :

Known as the newest and most powerful paradigms, object-oriented programming requires the designer to specify the data structures as well as the types of operations to be applied on those data structures. The pairing of data, and the operations that can be done on it is called an object. A program made using this language is therefore made up of a set of cooperating objects instead of an instructions list. The most famous object-oriented programming these days are C#, C , Visual Basic, Java, and Python.

o  Structured Programming   Languages :

An exceptional type of procedural programming, structured programming provides programmers with additional tools to handle the problems created by larger programs. When using this language, programmers are required to cut program structure into small pieces of code that can easily be understood. Instead of using global variables, it employs variables that are local to every subroutine. Among the popular features of structured programming is that it doesn't accept GOTO statement which is usually associated with the top-down approach. Such approach starts with an opening overview of the system with minimal details about the various parts. To add these details, design iterations are then included to complete the design. Commonly used structured languages include C, Pascal, and ADA.

o Procedural Programming Languages :

Procedural Programming involves a list of operations the program needs to complete to be able to attain the preferred state. It is a simple programming paradigm where every program comes with a starting phase, a list of tasks and operations, and an ending stage. Also called imperative programming, this approach comes with small sections of code that perform certain functions. These sections are made up of procedures, subroutines, or methods. A procedure is made up of a list of computations that should be done. Procedural programming lets a part of the code to be used again without the need to make several copies. It achieves this by dividing programmatic tasks into small sections. Because of this, programmers are also capable of maintaining and understanding program structure. Among the known procedural languages are BASIC and FORTRAN.

2. ASSEMBLERS, COMPILERS & INTERPRETERS

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o Assemblers: For an assembly language, a computer program to translate between lower-level representations of computer programs. An assembler converts basic computer instructions into a pattern of bits which can be easily understood by the computer and the processor can use it to perform its basic operations.

o Compilers: A compiler is a computer program (or set of programs) that transforms source written in a programming language (the source language) into another computer language (the target language, often having a binary form known as object code). The most common reason for wanting to transform source code is to create an executable program. The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a lower level language (e.g., assembly language or machine code). If the compiled program can run on a computer whose CPU or operating system is different from the one on which the compiler runs, the compiler is known as a cross-compiler. A program that translates from a low level language to a higher level one is adecompiler. A program that translates between high-level languages is usually called a language translator, source to source translator, orlanguage converter. A language rewriter is usually a program that translates the form of expressions without a change of language.

o Interpreters: An interpreter normally means a computer program that executes, i.e. performs, instructions written in a programming language. An interpreter may be a program that either

Executes the source code directly translates source code into some

efficient intermediate representation (code) and immediately executes this

explicitly executes stored precompiled code made by a compiler which is part of the interpreter system

OPERATING SYSTEMSMeaningOperating system is a integrated set of programs that control the resources (cpu,i/o devices etc. ) of a computer system and provides its

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users with an interface or virtual machine that is easier to use than the bare machine. it has two main objectives :-1) make a computer system easier to use2) manage the resources of computer system.

7. TYPES OF OPERATING SYSTEMS Batch Processing Operating System:In a batch processing

operating system interaction between the user and processor is limited or there is no interaction at all during the execution of work. Data and programs that need to be processed are bundled and collected as a ‘batch’ and executed together.

Multi-Tasking Operating System: In this type of OS several applications maybe simultaneously loaded and used in the memory. While the processor handles only one application at a particular time it is capable of switching between the applications effectively to apparently simultaneously execute each application. This type of operating system is seen everywhere today and is the most common type of OS, the Windows operating system would be an example.

Real-time Operating System: A real-time operating system processes inputs simultaneously, fast enough to affect the next input or process. Real-time systems are usually used to control complex systems that require a lot of processing like machinery and industrial systems.

Single User Operating System: A single user OS as the name suggests is designed for one user to effectively use a computer at a time.

Multi-User Operating System: This type of OS allows multiple users to simultaneously use the system, while here as well, the processor splits its resources and handles one user at a time, the speed and efficiency at which it does this makes it apparent that users are simultaneously using the system, some network systems utilize this kind of operating system.

Distributed Operating System: In a distributed system, software and data maybe distributed around the system, programs and files maybe stored on different storage devices which are located

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in different geographical locations and maybe accessed from different computer terminals.

DBMSCOMPONENTS OF DATABASE SYSTEMA database system is composed of four components;• Data• Hardware• Software• Users

1. Data   -  It is a very important component of the database system. Most of the organizations generate, store and process 1arge amount of data. The data acts a bridge between the machine parts i.e. hardware and software and the users which directly access it or access it through some application programs.

2. Hardware   -  The hardware consists of the secondary storage devices such as magnetic disks (hard disk, zip disk, floppy disks), optical disks (CD-ROM), magnetic tapes etc. on which data is stored together with the Input/Output devices (mouse, keyboard, printers), processors, main memory etc. which are used for storing and retrieving the data in a fast and efficient manner. Since database can range from those of a single user with a desktop computer to those on mainframe computers with thousand of users, therefore proper care should be taken for choosing appropriate hardware devices for a required database.

3. Software   -  The Software part consists of DBMS which acts as a bridge between the user and the database or in other words, software that interacts with the users, application programs, and database and files system of a particular storage media (hard disk, magnetic tapes etc.) to insert, update, delete and retrieve data. For performing these operations such as insertion, deletion and updation we can either use the Query Languages like SQL, QUEL, Gupta SQL or application softwares such as Visual 3asic, Developer etc.

4. Users   -  Users are those persons who need the information from the database to carry out their primary business responsibilities i.e. Personnel, Staff, Clerical, Managers, Executives etc. On the basis of the job and requirements made by them they are provided access to the database totally or partially.

Database management system concepts

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1 ) Data Definition Language  (DDL) statements are used to define the database structure or schema. A popular data manipulation language is that of Structured Query Language (SQL), which is used to retrieve and manipulate data in arelational database.Some examples:

o CREATE - to create objects in the databaseo ALTER - alters the structure of the databaseo DROP - delete objects from the databaseo TRUNCATE - remove all records from a table, including all spaces

allocated for the records are removedo COMMENT - add comments to the data dictionaryo RENAME - rename an object

Syntax : The create table statement does exactly that:

CREATE TABLE <table name> ( <attribute name 1> <data type 1>, ... <attribute name n> <data type n>);

The data types that you will use most frequently are character strings, which might be called VARCHAR or CHAR for variable or fixed length strings; numeric types such as NUMBER or INTEGER, which will usually specify a precision; and DATE or related types. Data type syntax is variable from system to system; the only way to be sure is to consult the documentation for your own software.

2) Data Manipulation Language (DML) statements are used for managing data within schema objects. The Data Manipulation Language (DML) is a subset of SQL programming language used to retrieve, insert and modify database information. These commands will be used by all database users during the routine operation of the database Some examples:

o SELECT - retrieve data from the a databaseo INSERT - insert data into a tableo UPDATE - updates existing data within a tableo DELETE - deletes all records from a table, the space for the

records remaino MERGE - UPSERT operation (insert or update)o CALL - call a PL/SQL or Java subprogramo EXPLAIN PLAN - explain access path to datao LOCK TABLE - control concurrency

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Syntax :

1)The insert statement is used, obviously, to add new rows to a table.

INSERT INTO <table name> VALUES (<value 1>, ... <value n>);

The comma-delimited list of values must match the table structure exactly in the number of attributes and the data type of each attribute. Character type values are always enclosed in single quotes; number values are never in quotes; date values are often (but not always) in the format 'yyyy-mm-dd' (for example, '2006-11-30').

Yes, you will need a separate INSERT statement for every row.

2) The update statement is used to change values that are already in a table.

UPDATE <table name> SET <attribute> = <expression> WHERE <condition>;

The update expression can be a constant, any computed value, or even the result of a SELECT statement that returns a single row and a single column. If the WHERE clause is omitted, then the specified attribute is set to the same value in every row of the table (which is usually not what you want to do). You can also set multiple attribute values at the same time with a comma-delimited list of attribute=expression pairs.

3) The delete statement does just that, for rows in a table.

DELETE FROM <table name> WHERE <condition>;

If the WHERE clause is omitted, then every row of the table is deleted (which again is usually not what you want to do)—and again, you will not get a “do you really want to do this?” message.

3) Data Control Language   (DCL ) statements DCL is abbreviation of Data Control Language. It is used to create roles, permissions, and referential integrity as well it is used to control access to database by securing it.. Some examples:

o GRANT - gives user's access privileges to databaseo REVOKE - withdraw access privileges given with the GRANT

command

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9. TRADITIONAL FILE CONCEPTS AND ENVIORNMENT

The traditional file-oriented approach to information processing has for each application a separate master file and its own set of personal files. COBOL language supported these file-oriented applications. It was used for developing applications such as of payroll, inventory, and financial accounting. However, in general an organization needs flow of information across these applications also and this requires sharing of data, which is very difficult to implement in the traditional file approach. In addition, a major limitation of file-based approach is that the programs are dependent on the files and the files are dependent upon the programs.These file-based approaches, which came into being as the first commercial applications of computers, suffered from the following significant disadvantages:

1. Data Redundancy: In a file system if an information is needed by two distinct applications, then it may be stored in two or more files. For example, the particulars of an employee may be stored in payroll and leave record applications separately. Some of this information may be changing, such as the address, the pay drawn, etc. It is therefore quite possible that while the address in the master file for one application has been updated the address in the master file for second application may have not been. Sometimes, it may not be easy to find that in how many files the repeating items such as the address has occurred. The solution, therefore, is to avoid this data redundancy by storing the address at just one place physically, and making it accessible to all applications.

2. Program/Data Dependency: In the traditional file oriented approach if a data field (attribute) is to be added to a master file, all such programs that access the master file would have to be changed to allow for this new field that would have been added to the master record. This is referred to as data dependence.

3. Lack of Flexibility: Since the data and programs are strong coupled in a traditional system, most information retrieval requests would be limited to well anticipated and pre-determined. The system would normally be capable of producing

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scheduled records and queries that it has been programmed to create. In the fast moving and competent business environment of today, apart from such regularly scheduled records, there is a need for responding to un-anticipatory queries and some kind of investigative analysis that could not have been envisaged professionally.

11. ER MODELLINGAn entity-relationship model (ERM) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in atop-down fashion. Diagrams created by this process are called entity-relationship diagrams, ER diagrams, or ERDs. An entity may be defined as a thing which is recognized as being capable of an independent existence and which can be uniquely identified. An entity is an abstraction from the complexities of some domain. When we speak of an entity we normally speak of some aspect of the real world which can be distinguished from other aspects of the real world. An entity may be a physical object such as a house or a car, an event such as a house sale or a car service, or a concept such as a customer transaction or order. Although the term entity is the one most commonly used, following Chen we should really distinguish between an entity and an entity-type. An entity-type is a category. An entity, strictly speaking, is an instance of a given entity-type. Examples: a computer, an employee, a song, a mathematical theorem.A relationship captures how two or more entities are related to one another. Relationships can be thought of as verbs, linking two or more nouns. Examples: an owns relationship between a company and a computer, a supervises relationship between an employee and a department, a performs relationship between an artist and a song, a proved relationship between a mathematician and a theorem.

: Two related entities

Entities and relationships can both have attributes. Examples: an employee entity might have a Social Security Number (SSN) attribute; the proved relationship may have a date attribute.Every entity (unless it is a weak entity) must have a minimal set of uniquely

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identifying attributes, which is called the entity's primary key.Entity-relationship diagrams don't show single entities or single instances of relations. Rather, they show entity sets and relationship sets. Example: a particular song is an entity. The collection of all songs in a database is an entity set. The eaten relationship between a child and her lunch is a single relationship. The set of all such child-lunch relationships in a database is a relationship set. In other words, a relationship set corresponds to a relation in mathematics, while a relationship corresponds to a member of the relation.

: An entity with an attribute

: A relationship with an attribute

: Primary key

12. INTEGRITY CONSTRAINTS

Integrity constraints are used to ensure accuracy and consistency of data in a relational database. Data integrity is handled in a relational database through the concept of referential integrity. There are many types of integrity constraints that play a role in referential integrity. Codd initially defined two sets of constraints but, in his second version of the relational model, he came up with five integrity constraints:

Entity integrity

The entity integrity constraint states that no primary key value can be null. This is because the primary key value is used to identify individual tuples in a relation . Having null value for the primary key implies that we cannot identify some tuples.This also specifies that there may not be any duplicate entries in primary key column key row.

Referential Integrity

The referential integrity constraint is specified between two relations and is used to maintain the consistency among tuple's in the two relations. Informally, the referential integrity constraint states that a tuple in one relation that refers to another relation must refer to an existing tuple in that relation.It is a rule that maintains consistency among the rows of the two relations

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Domain Integrity

The domain integrity states that every element from a relation should respect the type and restrictions of its corresponding attribute. A type can have a variable length which needs to be respected. Restrictions could be the range of values that the element can have, the default value if none is provided, and if the element can be NULL.

User Defined Integrity

e.g.: Age>=18 && Age<=60

Different keys in DBMS

1)Alternate key: An alternate key is any candidate key which is not selected to be the primary key . This is done to prevent incorrect data from entering a table (a duplicate entry is not valid in a unique column) and to make the database more complete and useful. These could be called alternate keys. 

2) Candidate key - A candidate key is a field or combination of fields that can act as a primary key field for that table to uniquely identify each record in that table. Eg:The table: Emloyee (Name, Address, Ssn, Employee_Id, Phone_ext ) In the above example Ssn no. and employee identity are candidate keys.

3) Compound key :compound key (also called a composite key or concatenated key) is a key that consists of 2 or more attributes. 

4) Primary key - a primary key is a value that can be used to identify a unique row in a table. Attributes are associated with it. Examples of primary keys are Social Security numbers (associated to a specific person) or ISBNs (associated to a specific book).  In the relational model of data, a primary key is a candidate key chosen as the main method of uniquely identifying a tuple in a relation. For Eg: Emloyee (Name,Address,Ssn,Employee_Idprimary_key,Phone_ext) 5) Foreign key - a foreign key (FK) is a field or group of fields in a database record that points to a key field or group of fields forming a key of another database record in some (usually different) table. Usually a foreign key in one table refers to the primary key (PK) of another table.

6) Surrogate keys : A surrogate key can be used as the primary key. In other situations there may be more than one candidate key for a relation, and no candidate key is obviously preferred. A surrogate key may be used as the primary key to avoid giving one candidate key artificial primacy over the others.

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Since primary keys exist primarily as a convenience to the programmer, surrogate primary keys are often used—in many cases exclusively—in database application design.

7) Unique key : a unique key can uniquely identify each row in a table, and is closely related to the Superkey concept. A unique key comprises a single column or a set of columns. No two distinct rows in a table can have the same value (or combination of values) in those columns if NULL values are not used. Depending on its design, a table may have arbitrarily many unique keys but at most one primary key.

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UNIT IIIDATA COMMUNICATION & NETWORK

1. CONCEPT OF DATA COMMUNICATION

These basic concepts of data communications are:

1.1. Send and Receive Data

Send/write data: A program sends a value for a data point, and the Data Hub records, or writes, the value for that point. This type of communication is synchronous. The send and the write are essentially two parts of a single process, so we use the terms pretty much interchangeably. You can write a value to the Data Hub manually using the Data Browser.

A typical write command from a program using DDE protocol is DDEPoke.

Receive/read data: A program requests to receive the value of a data point. The Data Hub then responds by sending the current value of the point. We call this reading the value from the Cascade Data Hub. Again, we sometimes use the two terms interchangeably, and again, this type of communication is synchronous.

A typical read command from a program using DDE protocol is DDERequest.

'Automatic' Receive: It is possible to set up live data channels, where a program receives updates on data points sent from the Cascade Data Hub. How it works is the program sends an initial request to the Data Hub to register for all changes to a data

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point. The Data Hub immediately sends the current value of the point, and then again whenever it changes. The Data Hub can receive data automatically in a similar way. This asynchronous type of communication is sometimes referred to as publish-subscribe.

A DDEAdvise command sets up this type of connection, which is called an advice loop.

1.1.2. Client - Server

Exchanging data with the Cascade DataHub is done through a client-server mechanism, where the client requests a service, and the server provides the service. Depending on the programs it interacts with, the DataHub is capable of acting as a client, as a server, or as both simultaneously.

The client-server relationship itself does not determine the direction of data flow. For example, a client may read data from the server, or it might write data to the server. The data can flow either way; the client might initiate a read or a write, and the server would respond.

1.1.3. Synchronous and Asynchronous Communication

Every type of communication, natural or man made comes in two basic forms: synchronous or asynchronous.

Synchronous communication means that for each message, the sender expects to get a reply from the receiver, like a telephone call. There is a back-and-forth exchange, so that each party knows that the other is receiving the message. If there is no response, you can be pretty sure that communication didn't occur.

Asynchronous communication means that a message gets sent but the receiver is not expected to reply, like a radio broadcast or a newspaper.

Each of these communication types has its own value and purpose in data communications, and the Cascade Data Hub is capable of both. The specific circumstances and application will determine which form of communication you end up using.

COMMUNICATION MEDIA

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Computer networks can be classified according to the hardware and associated software technology that is used to interconnect the individual devices in the network, such as electrical cable (Home PNA, power line communication, Ghn), optical fiber, and radio waves(wireless LAN).

A well-known family of communication media is collectively known as Ethernet. It is defined by IEEE 802 and utilizes various standards and media that enable communication between devices. Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves or infrared signals as a transmission medium.

Wired technologies

1) Twisted pair   wire  is the most widely used medium for telecommunication. Twisted-pair cabling consist of copper wires that are twisted into pairs. Ordinary telephone wires consist of two insulated copper wires twisted into pairs. Computer networking cabling (wired Ethernet as defined by IEEE 802.3) consists of 4 pairs of copper cabling that can be utilized for both voice and data transmission. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. The transmission speed ranges from 2 million bits per second to 10 billion bits per second. Twisted pair cabling comes in two forms which are Unshielded Twisted Pair (UTP) and Shielded twisted-pair (STP) which are rated in categories which are manufactured in different increments for various scenario.

2) Coaxial cable  is widely used for cable television systems, office buildings, and other work-sites for local area networks. The cables consist of copper or aluminum wire wrapped with insulating layer typically of a flexible material with a high dielectric constant, all of which are surrounded by a conductive layer. The layers of insulation help minimize interference and distortion. Transmission speed range from 200 million to more than 500 million bits per second.

3) ITU-T   G.hn   technology uses existing home wiring (coaxial cable, phone lines and power lines) to create a high-speed (up to 1 Gigabit/s) local area network.

4) Optical fiber   cable  consists of one or more filaments of glass fiber wrapped in protective layers that carries data by means of pulses of light. It transmits light which can travel over extended distances. Fiber-optic cables are not affected by electromagnetic radiation. Transmission speed

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may reach trillions of bits per second. The transmission speed of fiber optics is hundreds of times faster than for coaxial cables and thousands of times faster than a twisted-pair wire.

Wireless technologies

1) Terrestrial   microwave  – Terrestrial microwaves use Earth-based transmitter and receiver. The equipment looks similar to satellite dishes. Terrestrial microwaves use low-gigahertz range, which limits all communications to line-of-sight. Path between relay stations spaced approx, 48 km (30 mi) apart.

2) Communications   satellites  – The satellites use microwave radio as their telecommunications medium which are not deflected by the Earth's atmosphere. The satellites are stationed in space, typically 35,400 km (22,000 mi) (for geosynchronous satellites) above the equator. These Earth-orbiting systems are capable of receiving and relaying voice, data, and TV signals.

3) Cellular and PCS systems  – Use several radio communications technologies. The systems are divided to different geographic areas. Each area has a low-power transmitter or radio relay antenna device to relay calls from one area to the next area.

4) Wireless LANs  – Wireless local area network use a high-frequency radio technology similar to digital cellular and a low-frequency radio technology. Wireless LANs use spread spectrum technology to enable communication between multiple devices in a limited area.

5) Infrared communication  can transmit signals between devices within small distances of typically no more than 10 meters. In most cases,line-of-sight propagation is used, which limits the physical positioning of communicating devices.

6) A   global area network   (GAN ) is a network used for supporting mobile across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is handing off the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial wireless LANs

CONCEPT OF COMPUTER NETWORKS

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by

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communication channels that allow sharing of resources and information.

Networks may be classified according to a wide variety of characteristics such as the medium used to transport the data, communications protocol used, scale, topology, and organizational scope.

INTRANET & EXTRANETS

13(B) EXTRANETS

An extranet is a computer network that allows controlled access from the outside, for specific business or educational purposes. An extranet can be viewed as an extension of a company's intranet that is extended to users outside the company, usually partners, vendors, and suppliers. It has also been described as a "state of mind" in which the Internet is perceived as a way to do business with a selected set of other companies (business-to-business, B2B), in isolation from all other Internet users. In contrast, business-to-consumer (B2C) models involve known servers of one or more companies, communicating with previously unknown consumer users. An extranet is like a DMZ in that it provides access to needed services for channel partners, without granting access to an organization's entire network.

UNIT –IV: FUNCTIONAL AND ENTERPRISE SYSTEMS

1. DATA, INFORMATION & KNOWLEDGE CONCEPTS

The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data (plural of "datum") are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which information and then knowledge are derived. Raw data, i.e. unprocessed data, refers to a collection

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of numbers, characters, images or other outputs from devices that collect information to convert physical quantities into symbols.

Information in its most restricted technical sense is a message (utterance or expression) or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as signs, or conveyed as signals by waves. Information is any kind of event that affects the state of a dynamic system. The concept has numerous other meanings in different contexts.   Knowledge is a familiarity with someone or something, which can include information, facts, descriptions, and/or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject. It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); and it can be more or less formal or systematic.[1] In philosophy, the study of knowledge is called epistemology, and the philosopher Plato famously defined knowledge as "justified true belief." There is however no single agreed upon definition of knowledge, and there are numerous theories to explain it. Knowledge acquisition involves complex cognitive processes: perception, learning, communication, association and reasoning; while knowledge is also said to be related to the capacity of acknowledgment in human beings.

2. DECISION MAKING PROCESS

The figure given below suggests the steps in the decision-making process:-

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Identifying the Problem : Identification of the real problem before a business enterprise is the first step in the process of decision-making. It is rightly said that a problem well-defined is a problem half-solved. Information relevant to the problem should be gathered so that critical analysis of the problem is possible. This is how the problem can be diagnosed. Clear distinction should be made between the problem and the symptoms which may cloud the real issue. In brief, the manager should search the 'critical factor' at work. It is the point at which the choice applies. Similarly, while diagnosing the real problem the manager should consider causes and find out whether they are controllable or uncontrollable.

Analyzing the Problem : After defining the problem, the next step in the decision-making process is to analyze the problem in depth. This is necessary to classify the problem in order to know who must take the decision and who must be informed about the decision taken.

Uniqueness of the decision .: Collecting Relevant Data: After defining the problem and analyzing its nature, the next step is to obtain the relevant information/ data about it. There is information flood in the business world due to new developments in the field of information technology. All available information should be utilized fully for analysis of the problem. This brings clarity to all aspects of the problem.

Developing Alternative Solutions : After the problem has been defined, diagnosed on the basis of relevant information, the manager has to determine available alternative courses of action that could be used to solve the problem at hand. Only realistic alternatives should be considered. It is equally important to take into account time and cost constraints and psychological barriers that will restrict that number of alternatives. If necessary, group participation techniques may be used while developing alternative solutions as depending on one solution is undesirable.

Selecting the Best Solution : After preparing alternative solutions, the next step in the decision-making process is to select an alternative that seems to be most rational for solving the problem. The alternative thus selected must be communicated to those who are likely to be affected by it. Acceptance of the decision by group members is always desirable and useful for its effective implementation.

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Converting Decision into Action : After the selection of the best decision, the next step is to convert the selected decision into an effective action. Without such action, the decision will remain merely a declaration of good intentions. Here, the manager has to convert 'his decision into 'their decision' through his leadership. For this, the subordinates should be taken in confidence and they should be convinced about the correctness of the decision. Thereafter, the manager has to take follow-up steps for the execution of decision taken.

Ensuring Feedback : Feedback is the last step in the decision-making process. Here, the manager has to make built-in arrangements to ensure feedback for continuously testing actual developments against the expectations. It is like checking the effectiveness of follow-up measures. Feedback is possible in the form of organised information, reports and personal observations. Feed back is necessary to decide whether the decision already taken should be continued or be modified in the light of changed conditions.

3. PHYSICAL COMPONENTS OF INFORMATION SYSTEM

An information system is a system that accepts data resources as input

and processes them into information products as output. This

information system model highlights the relationships among the

components and activities of information systems. Information System Resources:(i) People Resources:People are required for the operation of all information systems. These people resources include:

End users (also called users or clients) are people who use an

information system or the information it produces. They can be

accountants, salespersons, engineers, clerks, customers, or

managers. Most of us are information system end users.

IS Specialists are people who develop and operate information

systems. They include systems analysts, programmers, computer

operators, and other managerial technical, and clerical IS personnel.

Briefly, systems analysts design information systems based on the

information requirements of end uses, programmers prepare

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computer programs based on the specifications of systems analysts,

and computer operators operate large computer systems.

(ii) Hardware Resources:The concept of Hardware resources includes all physical devices and materials used in information processing. Specially, it includes not only machines, such as computers and other equipment, but also all data media, that is, all tangible objects on which data is recorded, from sheets of paper to magnetic disks.

(iii) Software Resources:The concept of Software Resources includes all sets of information processing instructions. This generic concept of software includes not only the sets of operating instructions called programs, which direct and control computer hardware, but also the sets of information processing instructions needed by people, called procedures.It is important to understand that even information systems that don’t use computers have a software resource component. This is true even for the information systems of ancient times, or the manual and machine-supported information systems still used in the world today. They all require software resources in the form of information processing instructions and procedures in order to properly capture, process, and disseminate information to their users.iv) Data Resources:Data is more than the raw material of information systems. The concept of data resources has been broadened by managers and information systems professionals. They realize that data constitutes a valuable organization resource. Thus, you should view data as data resources that must be managed effectively to benefit all end users in an organization.Data can take many forms, including traditional alphanumeric data, composed of numbers and alphabetical and other characters that describe business transactions and other events and entities. Text data, consisting of sentences and paragraphs used in written communications; image data, such as graphic shapes and figures; and audio data, the human voice and other sounds, are also important forms of data.The data resources of information systems are typically organized into:

Database that hold processed and organized data.

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Knowledge bases that hold knowledge in variety of forms such as

facts, rules, and case examples about successful business practices.For example, data about sales transactions may be accumulated and stored in a sales database for subsequent processing that yields daily, weekly, and monthly sales analysis reports for management. Knowledge bases are used by knowledge management systems and expert systems to share knowledge and give expert advice on specific subjects.

4. CLASSIFICATION OF INFORMATION SYSTEM

Transaction Processing System (TPS): Applications of information systems that process business transaction data. Its use at operational level and focuses on the data. An example is a computer application for typing.

 Management Information System (MIS):Applications of information system that aims to provide information used in the field of management (management-oriented reporting.) Examples are computer applications for hospital services, pharmacy purchasing, scheduling of production machinery and others.

Decision Support System (DSS):Applications of information systems that provide decision-oriented information and especially in situations where decision-making. At the executive level often called Executive Information System. For example a computer application to determine the purchase of drug stocks at the hospital, the determination of sugar distribution system and others.

Expert System (ES):Information system designed to produce a decision by reproducing knowledge and expertise of the decision maker and problem solver and then simulate it. For example advanced applications of artificial neural networks, face recognition and so forth.

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Office automation system: Systems that support business activities on a large scale. Examples ERP applications for the company.

5. OVERVIEW OF SECURITY ISSUES IN INFORMATION TECHNOLOGY

Information security means protecting information and information systems from unauthorized access, use, disclosure, disruption, modification, perusal, inspection, recording or destruction. The terms information security, computer security and information assurance are frequently incorrectly used interchangeably. These fields are interrelated often and share the common goals of protecting the confidentiality, integrity and availability of information; however, there are some subtle differences between them.These differences lie primarily in the approach to the subject, the methodologies used, and the areas of concentration. Information security is concerned with the confidentiality, integrity and availability of data regardless of the form the data may take: electronic, print, or other forms.Computer security can focus on ensuring the availability and correct operation of acomputer system without concern for the information stored or processed by the computer.Governments, military, corporations, financial institutions, hospitals, and privatebusinesses amass a great deal of confidential information about their employees, customers, products, research, and financial status. Most of this information is now collected, processed and stored on electronic computers and transmitted acrossnetworks to other computers.Should confidential information about a business' customers or finances or new product line fall into the hands of a competitor, such a breach of security could lead to lost business, law suits or even bankruptcy of the business. Protecting confidential information is a business requirement, and in many cases also an ethical and legal requirement.For the individual, information security has a significant effect on privacy, which is viewed very differently in different cultures.The field of information security has grown and evolved significantly in recent years. There are many ways of gaining entry into the field as a career. It offers many areas for specialization including: securing network(s) and allied infrastructure, securing applications and databases,security testing, information systems auditing, business continuity planning and digital forensics science, etc.

6. EMERGING TRENDS OF INFORMATION TECHNOLOGY

Ten trends are identified consisting of aspects of: the difficulty of hiring qualified labor in-country; establishment of strategy resides entirely

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within the IT management; security remains a serious concern; offshore subcontractors sometimes place their employees within Icelandic companies; mid- and upper-level employees who can strategically develop networks and systems are in strong demand; use of information system (IS)/IT standards for information security is mostly voluntary; generally, the establishment of IS/IT strategy does not remain with board of directors; virtually all Icelandic corporations engage in, or have engaged in, outsourcing over the past five years (11 sub-trends are identified); and the business school curricula is inadequate to the needs of Icelandic corporations with respect to IT demands.

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