UNIVERSITY FOR DEVELOPMENT STUDIES FACULTY OF INTEGRATED DEVELOPMENT STUDIES

DEPARTMENT OF ECONOMICS AND ENTREPRENUERSHIP STUDIES

LECTURE NOTES

COURSE ID: EED 311

COURSE TITLE: Introduction to Computers and Computing

PREPARED BY:

Mark Atta Mensah (BSc. Computer Science) Senior Research Assistant

University for Development Studies Faculty of Integrated Development Studies

Department of Economics and Entrepreneurship Studies

OUTLINE OF COURSE

Course Description With no computer experience assumed, the course will expose students to the understanding

and application of knowledge in computers in relation to processing of documents as well as

undertaking simple quantitative analyses. The course content covers types of computers, the

computer hardware, the computer software, handling computers including safety precautions,

operating systems, booting, Windows, Microsoft Word, Microsoft Excel, Microsoft

PowerPoint presentation and Microsoft Access. By way of undertaking simple quantitative

analyses, students are introduced to IBM SPSS.

Objective The objectives for Introduction to Computers and Computing will enable the student to use

the computer effectively in a multitude of academic scenarios.

• Understand the basic parts of a computer system and their relationships

• Master the basic functions of the Windows operating system

• Understand and use basic computer terminology

• Master print commands to produce attractive hard copies of work

• Design document layouts that are creative and properly formatted

• Master the basic uses and procedures of word processing software

• Master the basic uses and procedures of spread sheet software

• Master the basic uses and procedures of presentation software

• Master the basic uses and procedures of specialised software – IBM SPSS

• Understand the rules and etiquette of Internet access and how to source for relevant

information from the internet

• Master the basic uses and procedures of Internet software

The course is will provide practical appreciation of computers and computing. It is also

expected to give students the interest to further develop and apply their skills in learning

activities and subsequently in their working environments.

Outline of Topics 1. Introduction to Computers and Information Processing Cycle

• What are Computers – Advantages and Limitations • About hardware and Software • Information Processing Cycle • Data and Information • The Role and types of Computers • Parts of a Computer • Using a Computer • Using a Keyboard • Using a Mouse

2. Introduction to Internet

• What is the Internet? • Types of Information you can access • Moving through a Web page • Hyperlinks • Internet Browsers • Internet addresses (URLs) • Communicating Using the Internet • Searching the Web • A Basic Search • Searching with Google • Evaluating Websites • Commonly used Internet terms

3. Word Processor

• About a Word Processor • Introduction to Microsoft Word • Creating and Managing Files • Editing and Formatting Text • Formatting Pages and Printing a Document • Creating Tables and adding graphics • Working with Styles • Working with Long Documents – Creating Table of Contents, List of Tables and

Figures and Page numbering. 4. Spread sheet

• About a Spread sheet • Working with the Excel Interface • Basic Workbook Skills • Formatting a Worksheet

• Managing Worksheets • Creating and Modifying Charts • Using Formulas and Functions • Printing Worksheets • Using the Help Function

5. Presentation (Graphics) Software • Introduction to Microsoft PowerPoint • Exploring the User Interface • Creating, Saving and Closing Presentation • Formatting a Presentation • Inserting Images • Viewing a Presentation in different ways • Previewing and Printing a Presentation • Essential tips for a successful Presentation

6. SPSS Statistics • Introduction to SPSS • Starting SPSS Statistics • Introducing the SPSS Interface • Entering and modifying Data • Descriptive Statistics • Data Manipulation • Reports • Charting your Data

Mode of Assessment:

Practical Exercises (*Assignments Inclusive): - 10%

Mid-Trimester Examination - 15%

End of Trimester Examination - 75%

UNIT 1: Introduction to Computers and Computing

INTRODUCTION

Definition: A Computer is an electronic device that can perform activities that involve

Mathematical, Logical and graphical manipulations. Generally, the term is used to describe a

collection of devices that function together as a system.

It performs the following three operations in sequence.

1. It receives data & instructions from the input device.

2. Processes the data as per instructions.

3. Provides the result (output) in a desired form.

Advantages of computers:

• High speed: Computers have the ability to perform routine tasks at a greater speed than

human beings. They can perform millions of calculations in seconds.

• Accuracy: Computers are used to perform tasks in a way that ensures accuracy.

• Storage: Computers can store large amount of information. Any item of data or any

instruction stored in the memory can be retrieved by the computer at lightning speeds.

• Automation: Computers can be instructed to perform complex tasks automatically

(which increases the productivity).

• Diligence: Computers can perform the same task repeatedly & with the same accuracy

without getting tired.

• Versatility: Computers are flexible to perform both simple and complex tasks.

• Cost effectiveness: Computers reduce the amount of paper work and human effort,

thereby reducing costs.

Limitations of computers:

• Computers need clear & c omplete instructions to perform a task accurately. If the

instructions are not clear & complete, the computer will not produce the required result.

• Computers cannot think.

• Computers cannot learn by experience.

Generations of Computers

Generation Component used First Generation (1946-1954 ) Vacuum tubes Second Generation (1955-1965) Transistors Third Generation (1968-1975 ) Integrated Circuits (IC) Fourth Generation ( 1976-1980) Very Large Scale Integrated Circuits

(VLSI) Fifth Generation (1980 – till today ) Ultra Scale Integrated Circuits (ULSI)

Micro Processor (SILICON CHIP)

Hardware and Software

Hardware: Computers work through an interaction of hardware and software. Hardware

refers to the parts of a computer that you can see and touch, including the case and everything

inside it. The most important piece of hardware is a tiny rectangular chip inside your

computer called the central processing unit (CPU), or microprocessor. It's the "brain" of your

computer—the part that translates instructions and performs calculations. Hardware items

such as your monitor, keyboard, mouse, printer, and other components are often called

hardware devices, or devices.

Software: It refers to the instructions, or programs, that tell the hardware what to do. The

most important software on t he computer is the operating system, which controls and

manages the hardware connected to your computer. The operating system provides an

interface that helps you to interact with the computer. A word processing program that you

can use to write letters on your computer is a type of software. The operating system (OS) is

software that manages your computer and the devices connected to it. Two well-known

operating systems are Windows and Macintosh operating system.

There are three categories of software namely:

• Systems Software: These are programs that coordinate the activities and functions of the

hardware and other programs. The system software acts as a m ediator between

application programs and the computer system’s hardware, as well as between the PC

and the user. The system software makes the physical machine do work. E.g. Operating

Systems, translators etc.

• Utility Software: It is system software designed to help analyze, configure, optimize or

maintain a computer. A single piece of utility software is usually called a utility or tool.

Utility software usually focuses on how the computer infrastructure (including the

b) Arithmetic Logic unit: Performs arithmetic and logical functions

c) Control Unit : Interprets program instructions and controls the input

and output devices

3. Output device: decodes information and presents it to the user

MEMORY OF THE COMPUTER Memory or storage capacity is one of the important components of a computer. Any storage

unit of a computer system is classified on the basis of the following criteria:

1. Access time: This is the time required to locate and retrieve stored data from the

storage unit in response to program instructions.

2. Storage capacity: It is the amount of data that can be stored in the storage unit.

3. Cost per bit of storage.

Units of memory:

The computer stores a character in the storage cells with binary (0, 1) mechanism. Thus the

basic unit of memory is a bit (binary digit – 0, 1). To store a character, a computer requires 8

bits or 1 byte. This is called the ― word length‖ of the storage unit. Hence the storage

capacity of the computer is measured in the number of words it can store and is expressed in

terms of bytes. The different units of measurement are

8 Bits = 1 Byte

210 (or) 1024 Bytes = 1 Kilo Byte (KB)

210 (or) 1024 KB = 1 Mega Byte (MB)

210 (or) 1024 MB = 1 Gega Byte (GB)

Types of Memory: A computer memory is of two types;

1. Primary Memory (Internal Storage): Primary memory is also called internal memory and

is an important part of a computer. It is the main area in a computer where the data is

stored. The stored data can be recalled instantly and correctly whenever desired. This

memory can be quickly accessed by the CPU for reading or storing information. Primary

memory is further classified into two types:

• Random Access Memory (RAM)

• Read- Only Memory (ROM )

RAM: RAM is also known as read/write memory as information can be read from and

written onto it. RAM is a place in a computer that holds instructions for the computer,

its programs and the data. The CPU can directly access the data from RAM almost

immediately. However, the storage of data and instructions in RAM is temporary, till the

time the computer is running. It disappears from RAM as soon as the power to the

computer is switched off i.e. it is volatile memory.

ROM: It is called Read-only memory as information can only be read from and not

written or changed onto ROM. ROM is the built-in-memory of a computer. It stores

some basic input – output instructions put by the manufacturer to operate the computer.

The storage of data and instructions in ROM is permanent. It does not depend on the

power supply i.e. it is non-volatile memory.

2. Secondary Memory (External storage): The primary memory which is faster (and hence

expensive) is generally not sufficient for large storage of data. As a result, additional

memory, called the ―auxiliary‖ or ―secondary memory‖ is used. It is also referred as

―backup storage‖ as it is used to store large volume of data on a permanent basis which

can be transferred to the primary memory whenever required for processing. Data are

stored in secondary storage in the same binary codes as in the main (primary memory)

storage. Some of the devices of secondary storages are Floppy Disk, Hard Disk, CD-

ROM, DVD and Flash drive.

Information Processing Cycle

This refers to the series of identifiable steps the computer goes through to accept and process

data into information, store the information for future use, and/or share it with others. This

process is divided into four (4) basic steps, which include; Input, Process, Output, Storage,

and communication.

Input: -This is any data or instruction you enter into a computer. This is done by means of

input devices. The six commonly used input devices are, the keyboard, mouse, scanner,

microphone, digital camera, and PC camera

Process: - this is the interpretation and manipulation performed on data and instructions to

produce a result (information). This task is performed by the Central Procession Unit (CPU).

Output: - This is any data that has been processed into information. The output devices of

the computer are responsible for this task, examples of which include; monitor, printer, and

speakers.

Storage: - This is an area in a computer that can hold data and information for future use.

Examples of the commonly used storage devices include; Hard Disk drive (HDD), Compact

disk (CD), DVD, Floppy Disk Drive, and Pen Drives.

Data and Information Data

All computer processing requires data, which is a collection of raw facts, figures and symbols

given to the computer during the input phase. Example: Names of students and their marks

in different subjects listed in random order.

Information

Computers manipulate data to create information. Information is data that is processed and

presented in an organized, meaningful manner for use. Example: When the names of students

are arranged in alphabetical order, total and average marks are calculated & presented in a

tabular form, it is information.

During the output phase, the information that has been created is put into some form, such as

a printed report. The information can also be put in computer storage for future use.

Parts of a computer A computer is a system of many parts working together. The physical parts, which you can

see and touch, are collectively called hardware. (Software, on the other hand, refers to the

instructions, or programs, that tell the hardware what to do.)

The illustration below shows the most common hardware in a desktop computer system. A

laptop computer has similar parts but combines them into a single notebook-sized package.

Desktop computer system

System unit The system unit is the core of a computer system. Usually it's a rectangular box placed on or

underneath your desk. Inside this box a re many electronic components that process

information. The most important of these components is the central processing unit (CPU),

or microprocessor, which acts as the "brain" of your computer. Another component is

random access memory (RAM), which temporarily stores information that the CPU uses

while the computer is on. The information stored in RAM is erased when the computer is

turned off.

Almost every other part of your computer connects to the system unit using cables. The

cables plug into specific ports (openings), typically on the back of the system unit. Hardware

that is not part of the system unit is sometimes called a peripheral device or device.

System unit

Storage Your computer has one or more disk drives—devices that store information on a metal or

plastic disk. The disk preserves the information even when your computer is turned off.

Hard disk drive The computer's hard disk drive stores information on a hard disk, a rigid platter or stack of

platters with a magnetic surface. Because hard disks can hold massive amounts of

information, they usually serve as your computer's primary means of storage, holding almost

all of your programs and files. The hard disk drive is normally located inside the system unit.

Hard disk drive

CD and DVD drives CD-ROM stands for Compact Disk–Read Only Memory. It is used to store a wide variety of

information. Its main advantage is that it is portable and can hold a large amount of data. The

storage capacity of most CD-ROMs is approximately 650 MB or 700 MB.

CD-ROMs have the following variations:

a) CD-R (Compact disc Recordable): Data can be written onto it just once. The stored data

can be read. Data once written onto it cannot be erased.

b) CD-RW (Compact disc Rewritable): It is also called erasable CD. Data once written

onto it can be erased to write or record new information many times.

To use a CD-ROM, a device called CD drive is needed.

CD-ROM CD Drive

DVD stands for Digital Versatile Disc. It is similar to a CD-ROM, except that it can store

larger amounts of data. The storage capacity of a DVD is at least 4.7GB. DVDs that can store

up to 17GBs are also available. Because of their capacity, DVDs are generally used to store a

very large multimedia presentations and movies that combine high quality sound and

graphics.

Floppy disk drive Floppy disk drives store information on floppy disks, also called floppies or diskettes.

Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also

retrieve information more slowly and are more prone to damage. For these reasons, floppy

disk drives are less popular than they used to be, although some computers still include them.

Floppy disk

Why are floppy disks "floppy"? Even though the outside is made of hard plastic, that's just

the sleeve. The disk inside is made of a thin, flexible vinyl material.

Mouse It is a device that controls the movement of the cursor on a monitor. A mouse will have 2

buttons on its top. The left button is the most frequently used button. There will be a wheel

between the left and right buttons. This wheel enables us to smoothly scroll through screens

of information. As we move the mouse, the pointer on the monitor moves in the same

direction. Optical mouse is another advanced pointing device that uses a light emitting

component instead of the mouse ball. Mouse cannot be used for entering the data. It is only

useful to select the options on the screen.

Mouse

A mouse usually has two buttons: a primary button (usually the left button) and a secondary

button. Many mice also have a wheel between the two buttons, which allows you to scroll

smoothly through screens of information.

When you m ove the mouse with your hand, a pointer on your screen moves in the same

direction. (The pointer's appearance might change depending on where it's positioned on your

screen.) When you w ant to select an item, you poi nt to the item and then click (press and

release) the primary button. Pointing and clicking with your mouse is the main way to

interact with your computer.

Keyboard The Key board is used for typing text into the computer. It is also known as standard Input

device. A computer keyboard is similar to that of a type writer with additional keys. The most

commonly available computer keyboard has 104 keys. There are different types of keys on

the keyboard. The keys are categorized as:

• Alphanumeric keys, including letters & numbers.

• Punctuation keys, such as colon (:), semicolon (;) Question mark (?), Single & double

quotes (‗,‖)

• Special keys such as arrow keys, control keys, function keys (F1 to F12), HOME,

END etc.

Keyboard

You can also use your keyboard to perform many of the same tasks you can perform with a

mouse.

Monitor A monitor displays information in visual form, using text and graphics. The portion of the

monitor that displays the information is called the screen. Like a t elevision screen, a

computer screen can show still or moving pictures.

There are two basic types of monitors: CRT (cathode ray tube) monitors and LCD (liquid

crystal display) monitors. Both types produce sharp images, but LCD monitors have the

advantage of being much thinner and lighter. CRT monitors, however, are generally more

affordable.

LCD monitor (left); CRT monitor (right)

Printer A printer transfers data from a computer onto paper. The two main types of printers are inkjet

printers and laser printers. Inkjet printers are the most popular printers. They can print in

black and white or in full colour and can produce high-quality photographs when used with

special paper. Laser printers are faster and generally better able to handle heavy use.

Inkjet printer (left); laser printer (right)

Speakers Speakers are used to play sound. They may be built into the system unit or connected with

cables. Speakers allow you to listen to music and hear sound effects from your computer.

Computer speakers

Modem To connect your computer to the Internet, you need a modem. A modem is a device that sends

and receives computer information over a telephone line or high-speed cable. Modems are

sometimes built into the system unit, but higher-speed modems are usually separate

components.

Cable modem

Types of computers

Computers range in size and capability. Different types of computers are available in the

market today. The most common computer is the Personal Computer (PC), typically used by

individuals and small businesses. A personal computer is a computer that is designed for use

by one person at a time. A personal computer is used in the workplace to create documents,

manage business records, and communicate with others. It is used in schools to teach lessons,

research over the Internet, and work on assignments. You can also use a personal computer to

play games, view videos, and listen to music. Depending on the size and the purpose of a

personal computer, it can be categorized into four different types: desktop, laptop, handheld,

or tablet.

You select a computer depending on the tasks that you want it to perform. For example, if

you want to use the computer to edit photos or play complex games, you need a computer

with a fast CPU and a good display adapter.

Desktop computers Desktop computers are designed for use at a desk or table. They are typically larger and more

powerful than other types of personal computers. Desktop computers are made up of separate

components. The main component, called the system unit, is usually a rectangular case that

sits on or underneath a desk. Other components, such as the monitor, mouse, and keyboard,

connect to the system unit.

Desktop computer

Laptop computers Laptop computers are lightweight mobile PCs with a t hin screen. They are often called

notebook computers because of their small size. Laptops can operate on batteries, so you can

take them anywhere. Unlike desktops, laptops combine the CPU, screen, and keyboard in a

single case. The screen folds down onto the keyboard when not in use.

Laptop computer

Handheld computers Handheld computers, also called personal digital assistants (PDAs), are battery-powered

computers small enough to carry almost anywhere. Although not as powerful as desktops or

laptops, handhelds are useful for scheduling appointments, storing addresses and phone

numbers, and playing games. Some have more advanced capabilities, such as making

telephone calls or accessing the Internet. Instead of keyboards, handhelds have touch screens

that you use with your finger or a stylus (a pen-shaped pointing tool).

Handheld computer

Tablet PCs Tablet PCs are mobile PCs that combine features of laptops and handhelds. Like laptops,

they're powerful and have a built-in screen. Like handhelds, they allow you to write notes or

draw pictures on t he screen, usually with a tablet pen instead of a st ylus. They can also

convert your handwriting into typed text. Some Tablet PCs are “convertibles” with a screen

that swivels and unfolds to reveal a keyboard underneath.

Tablet PC

The Role of Computers Computers play a major role in our daily lives. They are used in industries, schools,

government offices, and shops. You can use computers to communicate with your family and

friends, create a household budget, book travel and movie tickets, or manage your business.

In business and industry, you use computers to maintain accounts, create personnel records,

track inventory, prepare presentations and reports, manage projects, and communicate by e-

mail.

You can use computers to design any type of publication ranging from simple newsletters to

fashion magazines, marketing materials, books, or newspapers.

In the field of education, trainers can use computers to deliver training through audio-visual

learning aids, maintain student records to track performance, search for information on

different topics, and create or submit assignments.

In government organizations, you use computers to organize information by s toring and

updating records. Computers are also used for providing services to citizens. For example,

you can view information on current policies and government issues on a computer.

In the field of medicine, doctors use computers to review medical records of patients. Doctors

also use computers to find information about the latest drugs available to treat a disease.

Doctors can also use computer technology to discuss and share information about various

diseases.

You can use computers to view the details of your bank account. Traders use computer

technology to get instant information on s tock markets, to trade stocks, and to manage

investments.

Scientists use computers for scientific research, and to gather and analyse information. For

example, they use computers to view images from space and to publish information on their

recent research.

You can also use computers to create drawings and paintings. Photographers use computers

to edit and enhance pictures. Writers use computers to write content for their books and to

also create illustrations. By using computers, writers can make changes in the content easily

and save a lot of time.

In the field of entertainment, you can use computers to listen to music, watch movies, store

and print photographs, send greetings, and play games.

Using the Computer

To turn on a computer, press the power button on t he system unit. When you t urn on t he

computer, lights on the keyboard may blink briefly and you may also hear a beep. This is an

indication that the power-on self-test (POST) has started.

The computer performs a sequence of quick tests to check whether the motherboard, memory,

hard drive, and other components are working.

If you hear a series of beeps, the monitor may display a message indicating that a component

is not functioning. For example, if the keyboard cable is not attached, an error message may

report that there is no keyboard detected.

After POST, the computer starts the operating system, and then displays the logon screen.

You now log on t o the Microsoft® Windows® 7 operating system. The operating system

allows you to instruct the computer what to do after you have turned it on.

The operating system controls the computer’s hardware and also manages the computer’s

operations and tasks, such as logging on, logging off, and shutting down.

For example, to log on to Windows 7, you need to type your user name and password. The

settings for the user account are applied and you are now logged on to Windows 7. After you

log on, you can perform various tasks, such as creating a new file or modifying an existing

file.

After performing the required tasks, you need to save the changes you made to the file. You

can then log off from Windows 7. To log off, you need to click Start, and then click Log Off.

To securely turn off your computer, you must shutdown Windows 7. To do this, you need to

click Start, and then, at the bottom of the Start menu, click the Shutdown button.

If you e ncounter problems while using the computer, you can choose the Restart option to

restart the computer. To do this, click Restart in the Shutdown Windows dialog box.

On most computers, you should never use the actual power button on the front of the system

unit to turn off the computer unless it stops responding.

Using the Keyboard Whether you're writing a letter or entering numerical data, your keyboard is the main way to

enter information into your computer. This article covers the basics of keyboard operation and

gets you started with keyboard commands.

Organisation of Keyboard Keys The keys on your keyboard can be divided into several groups based on function:

• Typing (alphanumeric) keys. These keys include the same letter, number, punctuation,

and symbol keys found on a traditional typewriter.

• Control keys. These keys are used alone or in combination with other keys to perform

certain actions. The most frequently used control keys are CTRL, ALT, the

Windows logo key , and ESC.

• Function keys. The function keys are used to perform specific tasks. They are labelled as

F1, F2, F3, and so on, up to F12. The functionality of these keys differs from program to

program.

• Navigation keys. These keys are used for moving around in documents or webpages and

editing text. They include the arrow keys, HOME, END, PAGE UP, PAGE DOWN,

DELETE, and INSERT.

• Numeric keypad. The numeric keypad is handy for entering numbers quickly. The keys

are grouped together in a block like a conventional calculator or adding machine.

The following illustration shows how these keys are arranged on a typical keyboard. Your

keyboard layout may differ.

How the keys are arranged on a keyboard

Using keyboard shortcuts Keyboard shortcuts are ways to perform actions by using your keyboard. They're called

shortcuts because they help you work faster. In fact, almost any action or command you can

perform with a mouse can be performed faster using one or more keys on your keyboard.

In Help topics, a plus sign (+) between two or more keys indicates that those keys should be

pressed in combination. For example, CTRL+A means to press and hold CTRL and then press

A. CTRL+SHIFT+A means to press and hold CTRL and SHIFT and then press A.

Numeric keypad

To use the numeric keypad to enter numbers, press NUM LOCK. Most keyboards have a light

that indicates whether NUM LOCK is on or off. When NUM LOCK is off, the numeric

keypad functions as a second set of navigation keys (these functions are printed on the keys

next to the numerals or symbols).

You can use your numeric keypad to perform simple calculations with Calculator.

Three odd keys

So far, we've discussed almost every key you're likely to use. But for the truly inquisitive, let's

explore the three most mysterious keys on the keyboard: PRINT SCREEN, SCROLL LOCK,

and PAUSE/BREAK.

PRINT SCREEN (or PRT SCN)

A long time ago, this key actually did what it says—it sent the current screen of text to your

printer. Nowadays, pressing PRINT SCREEN captures an image of your entire screen (a

"screen shot") and copies it to the Clipboard in your computer's memory. From there you can

paste it (CTRL+V) into Microsoft Paint or another program and, if you want, print it from that

program.

Tip

Press ALT+PRINT SCREEN to capture an image of just the active window, instead of the

entire screen.

SCROLL LOCK (or SCR LK)

In most programs, pressing SCROLL LOCK has no e ffect. In a few programs, pressing

SCROLL LOCK changes the behaviour of the arrow keys and the PAGE UP and PAGE

DOWN keys; pressing these keys causes the document to scroll without changing the position

of the cursor or selection. Your keyboard might have a light indicating whether SCROLL

LOCK is on.

PAUSE/BREAK

This key is rarely used. In some older programs, pressing this key pauses the program or, in

combination with CTRL, stops it from running.

Other keys

Some modern keyboards come with "hot keys" or buttons that give you qui ck, one-press

access to programs, files, or commands. Other models have volume controls, scroll wheels,

zoom wheels, and other gadgets. For details about these features, check the information that

came with your keyboard or computer, or go to the manufacturer's website.

Tips for using your keyboard safely

Using your keyboard properly can help avoid soreness or injury to your wrists, hands, and

arms, particularly if you use your computer for long periods of time. Here are some tips to

help you avoid problems:

• Place your keyboard at elbow level. Your upper arms should be relaxed at your sides.

• Center your keyboard in front of you. If your keyboard has a numeric keypad, you can

use the spacebar as the centring point.

• Type with your hands and wrists floating above the keyboard, so that you can use your

whole arm to reach for distant keys instead of stretching your fingers.

• Avoid resting your palms or wrists on any type of surface while typing. If your keyboard

has a palm rest, use it only during breaks from typing.

• While typing, use a light touch and keep your wrists straight.

• When you're not typing, relax your arms and hands.

• Take short breaks from computer use every 15 to 20 minutes.

Using the Mouse Just as you would use your hands to interact with objects in the physical world, you can use

your mouse to interact with items on your computer screen. You can move objects, open

them, change them, throw them away, and perform other actions, all by pointing and clicking

with your mouse. A mouse can therefore be defined as a small device that you can use to

move, select, and open items displayed on your monitor.

Basic parts

A mouse typically has two buttons: a primary button (usually the left button) and a secondary

button (usually the right button). The primary button is the one you will use most often. Most

mice also include a scroll wheel between the buttons to help you s croll through documents

and webpages more easily. On some mice, the scroll wheel can be pressed to act as a third

button. Advanced mice might have additional buttons that can perform other functions.

Parts of a mouse

Holding and moving the mouse

Place your mouse beside your keyboard on a cl ean, smooth surface, such as a m ouse pad.

Hold the mouse gently with your index finger resting on the primary button and your thumb

resting on the side. To move the mouse, slide it slowly in any direction. Don't twist it—keep

the front of the mouse aimed away from you. As you move the mouse, a pointer (see picture)

on your screen moves in the same direction. If you run out of room to move your mouse on

your desk or mouse pad, just pick up the mouse and bring it back closer to you.

Hold the mouse lightly, keeping your

wrist straight

Pointing, clicking, and dragging

Pointing to an item on the screen means moving your mouse so the pointer appears to be

touching the item. When you point to something, a small box often appears that describes the

item. For example, when you point to the Recycle Bin on the desktop, a box appears with this

information: "Contains the files and folders that you have deleted."

Pointing to an object often

reveals a descriptive message about it

The pointer can change depending on what you're pointing to. For example, when you point

to a link in your web browser, the pointer changes from an arrow to a hand with a pointing

finger .

Most mouse actions combine pointing with pressing one of the mouse buttons. There are four

basic ways to use your mouse buttons: clicking, double-clicking, right-clicking, and dragging.

Clicking (single-clicking) To click an item, point to the item on the screen, and then press and release the primary button

(usually the left button).

Clicking is most often used to select (mark) an item or open a m enu. This is sometimes

called single-clicking or left-clicking.

Double-clicking To double-click an item, point to the item on the screen, and then click twice quickly. If the

two clicks are spaced too far apart, they might be interpreted as two individual clicks rather

than as one double-click.

Double-clicking is most often used to open items on your desktop. For example, you can start

a program or open a folder by double-clicking its icon on the desktop.

Right-clicking To right-click an item, point to the item on the screen, and then press and release the

secondary button (usually the right button).

Right-clicking an item usually displays a list of things you can do with the item. For example,

when you r ight-click the Recycle Bin on your desktop, Windows displays a menu allowing

you to open it, empty it, delete it, or see its properties. If you're ever unsure of what to do with

something, right-click it.

Right-clicking the Recycle Bin opens a menu of

related commands

Dragging You can move items around your screen by dragging them. To drag an object, point to the

object on the screen, press and hold the primary button, move the object to a new location,

and then release the primary button.

Dragging (sometimes called dragging and dropping) is most often used to move files and

folders to a different location and to move windows and icons around on your screen.

Using the scroll wheel If your mouse has a scroll wheel, you can use it to scroll through documents and webpages.

To scroll down, roll the wheel backward (toward you). To scroll up, roll the wheel forward

(away from you).