LESSON 1: INTRODUCTION TO COMPUTERS - … 301 – Introduction to Computers & Computing Page 1 LESSON 1: INTRODUCTION TO COMPUTERS LESSON CONTENTS What are Computers About hardware

eed 301 – Introduction to Computers & Computing Page 1

LESSON 1:

INTRODUCTION TO COMPUTERS

LESSON CONTENTS

� What are Computers � About hardware and Software � The Role of Computers � Parts of a Computer � Using a Computer � Using a Keyboard � Using a Mouse

LESSON OBJECTIVES

After completing this lesson, you will be able to:]

• Know what the computer is made up of • Understand Information Processing Cycle • Distinguish between Hardware and Software • Describe the importance of computers in today’s world. • Identify some types of Computers • Identify the main parts of a computer. • Identify the steps for starting a computer. • Identify the different groups of keys on a keyboard. • Perform different tasks by using a mouse.


What are computers?

Computers are machines or an electronic device that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

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 refers to the instructions, or programs, that tell the hardware what to do. The most important software on the 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. Your computer uses the Windows operating system.

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

All computer processing requires data, which is a collection of raw facts, figures and symbols, such as numbers, words, images, video and sound, given to the computer during the input phase. Computers manipulate data to create information. Information is data that is organized, meaningful, and useful. 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.

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 thin 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 the screen, usually with a tablet pen instead of a stylus. 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 storing 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 stock markets, to trade stocks, and to manage investments.

Scientists use computers for scientific research, and to gather and analyze 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.

Parts of a computer

If you use a desktop computer, you might already know that there isn't any single part called the "computer." A computer is really 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. Your system may look a little different, but it probably has most of these parts. 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 are 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

Nearly all computers today come equipped with a CD or DVD drive, usually located on the front of the system unit. CD drives use lasers to read (retrieve) data from a CD, and many CD drives can also write (record) data onto CDs. If you have a recordable disk drive, you can store copies of your files on blank CDs. You can also use a CD drive to play music CDs on your computer.

CD

DVD drives can do everything that CD drives can, plus read DVDs. If you have a DVD drive, you can watch movies on your computer. Many DVD drives can record data onto blank DVDs.

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

A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless.

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 move 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 want to select an item, you point 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

A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys:

• The function keys, found on the top row, perform different functions depending on where they are used.

• The numeric keypad, located on the right side of most keyboards, allows you to enter numbers quickly.

• The navigation keys, such as the arrow keys, allow you to move your position within a document or webpage.


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 television 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. You don't need a printer to use your computer, but having one allows you to print e-mail, cards, invitations, announcements, and other materials. Many people also like being able to print their own photos at home.

The two main types of printers are inkjet printers and laser printers. Inkjet printers are the most popular printers for the home. They can print in black and white or in full color 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


All the named parts of the computer can generally be grouped under five (5) major categories. These are input devices, output devices, central processing unit and memory, motherboard, expansion cards and storage devices.

Part Description

Input Devices

You use input devices to provide information to a computer, such as typing a letter or giving instructions to a computer to perform a task. Some examples of input devices are described in the following list.

• Mouse: A device that you use to interact with items displayed on the computer screen. A standard mouse has a left and a right button. You use the left button to select items and provide instructions by clicking an active area on the screen. You use the right button to display commonly used menu items on the screen.

• Keyboard: A set of keys that resembles a typewriter keyboard. You use the keyboard to type text, such as letters or numbers into the computer.

• Microphone: A device that you can use to talk to people in different parts of the world. You can record sound into the computer by using a microphone. You can also use a microphone to record your speech and let the computer convert it into text.

• Scanner: A device that is similar to a photocopy machine. You can use this device to transfer an exact copy of a photograph or document into a computer. A scanner reads the page and translates it into a digital format, which a computer can read. For example, you can scan photographs of your family using a scanner.

• Webcam: A device that is similar to a video camera. It allows you to capture and send the live pictures to the other user. For example, a webcam allows your friends and family to see you when communicating with them.

Output Devices

You use output devices to get feedback from a computer after it performs a task. Some examples of output devices are described in the following list. • Monitor: A device that is similar to a television. It is used to

display information, such as text and graphics, on the computer.

• Printer: A device that you use to transfer text and images from a computer to a paper or to another medium, such as a transparency film. You can use a printer to create a paper copy of whatever you see on your monitor.

• Speaker/Headphone: Devices that allow you to hear sounds. Speakers may either be external or built into the computer.


Central Processing Unit and Memory

The central processing unit (CPU) is a device that interprets and runs the commands that you give to the computer. It is the control unit of a computer. The CPU is also referred to as the processor.

• Memory is where information is stored and retrieved by the CPU. There are two main types of memory.

• Random Access Memory (RAM): It is the main memory and allows you to temporarily store commands and data. The CPU reads data and commands from RAM to perform specific tasks. RAM is volatile, which means it is available only while the computer is turned on. The contents of RAM must be copied to a storage device if you want to save the data in the RAM.

• Read Only Memory (ROM): It is the memory that retains its contents even after the computer is turned off. ROM is non-volatile, or permanent, memory that is commonly used to store commands, such as the commands that check whether everything is working properly.

Motherboard

The motherboard is the main circuit board inside the computer. It has tiny electronic circuits and other components on it. A motherboard connects input, output, and processing devices together and tells the CPU how to run. Other components on the motherboard include the video card, the sound card, and the circuits that allow the computer to communicate with devices like the printer. The motherboard is sometimes called a system board.

Storage Devices

You use storage devices to store computer information. Storage devices come in many forms. Some examples are hard drive or disk, CD-ROM, floppy disk, and DVD- ROM. Storage devices can be divided into two types, internal storage devices and external storage devices.

Some common storage devices are described in the following list.

Hard Disk: A magnetic disk that is usually the main storage device on most computers. It can be an external or an internal device.

Floppy Disk: A portable storage device that allows you to store a small amount of data. A disadvantage of this disk is that it can be easily damaged by heat, dust, or magnetic fields.

CD-ROM: A portable storage medium that allows you to store 400 times more data than on a floppy disk. It is less prone to damage than a floppy disk.

DVD-ROM: A portable storage medium that is similar to a CD-ROM; however, it can store larger amounts of data than a floppy disk or a CD- ROM. A DVD-ROM is commonly used to store movies and videos.


Using the Computer

To turn on a computer, press the power button on the system unit. When you turn on the 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 to 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 encounter 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

Using your keyboard

Whether you're writing a letter or entering numerical data, your keyboard is the main way to enter information into your computer. But did you know you can also use your keyboard to control your computer? Learning just a few simple keyboard commands (instructions to your computer) can help you work more efficiently. This article covers the basics of keyboard operation and gets you started with keyboard commands.

How the keys are organized

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 labeled 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

Typing text

Whenever you need to type something in a program, e-mail message, or text box, you'll see a blinking vertical line ( ). That's the cursor, also called the insertion point. It shows where the text that you type will begin. You can move the cursor by clicking in the desired location with the mouse, or by using the navigation keys (see the "Using navigation keys" section of this article).

In addition to letters, numerals, punctuation marks, and symbols, the typing keys also include SHIFT, CAPS LOCK, the TAB key, ENTER, the SPACEBAR, and BACKSPACE.

Key name How to use it

SHIFT Press SHIFT in combination with a letter to type an uppercase letter. Press SHIFT in combination with another key to type the symbol shown on the upper part of that key.


CAPS LOCK Press CAPS LOCK once to type all letters as uppercase. Press CAPS LOCK again to turn this function off. Your keyboard may have a light indicating whether CAPS LOCK is on.

TAB Press the TAB key to move the cursor several spaces forward. You can also press the TAB key to move to the next text box on a form.

ENTER Press ENTER to move the cursor to the beginning of the next line. In a dialog box, press ENTER to select the highlighted button.

SPACEBAR Press the SPACEBAR to move the cursor one space forward.

BACKSPACE Press BACKSPACE to delete the character before the cursor, or the selected text.

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.

Find program shortcuts

You can do things in most programs by using the keyboard. To see which commands have keyboard shortcuts, open a menu. The shortcuts (if available) are shown next to the menu items.


Keyboard shortcuts appear next to menu items

Useful shortcuts

The following table lists some of the most useful keyboard shortcuts.

Press this To do this

Windows logo key

Open the Start menu

ALT+TAB Switch between open programs or windows

ALT+F4 Close the active item, or exit the active program

CTRL+S Save the current file or document (works in most programs)

CTRL+C Copy the selected item

CTRL+X Cut the selected item

CTRL+V Paste the selected item

CTRL+Z Undo an action

CTRL+A Select all items in a document or window


F1 Display Help for a program or Windows

Windows logo key +F1

Display Windows Help and Support

ESC Cancel the current task

Application key Open a menu of commands related to a selection in a program. Equivalent to right-clicking the selection.

Using navigation keys

The navigation keys allow you to move the cursor, move around in documents and webpages, and edit text. The following table lists some common functions of these keys.

Press this To do this

LEFT ARROW, RIGHT ARROW, UP ARROW, or DOWN ARROW

Move the cursor or selection one space or line in the direction of the arrow, or scroll a webpage in the direction of the arrow

HOME Move the cursor to the beginning of a line or move to the top of a webpage

END Move the cursor to the end of a line or move to the bottom of a webpage

CTRL+HOME Move to the top of a document

CTRL+END Move to the bottom of a document

PAGE UP Move the cursor or page up one screen

PAGE DOWN Move the cursor or page down one screen

DELETE Delete the character after the cursor, or the selected text; in Windows, delete the selected item and move it to the Recycle Bin


INSERT Turn Insert mode off or on. When Insert mode is on, text that you type is inserted at the cursor. When Insert mode is off, text that you type replaces existing characters.

Using the numeric keypad

The numeric keypad arranges the numerals 0 through 9, the arithmetic operators + (addition), - (subtraction), * (multiplication), and / (division), and the decimal point as they would appear on a calculator or adding machine. These characters are duplicated elsewhere on the keyboard, of course, but the keypad arrangement allows you to rapidly enter numerical data or mathematical operations with one hand.

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 effect. 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 quick, 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 centering 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.

Create keyboard shortcuts to open programs

You can create keyboard shortcuts to open programs, which can often be simpler than opening programs using your mouse or other pointing device. Before completing these steps, verify that a


shortcut was created for the program to which you want to assign a keyboard shortcut. If no shortcut was created, browse to the folder that contains the program, right-click the program file, and then click Create Shortcut to create one.

1. Locate the shortcut to the program for which you want to create a keyboard shortcut.

2. Right-click the shortcut and then click Properties.

3. In the Shortcut Properties dialog box, click the Shortcut tab, and then click the Shortcut key box.

4. Press the key on your keyboard that you want to use in combination with CTRL+ALT (keyboard shortcuts automatically start with CTRL+ALT), and then click OK. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

You can now use this keyboard shortcut to open the program when you're using the desktop. The shortcut will also work while using some programs, though it might not work with some programs that have their own keyboard shortcuts.

Notes

• The Shortcut key box will display None until you select the key, and then the box will display Ctrl+Alt followed by the key you selected.

• You cannot use the ESC, ENTER, TAB, SPACEBAR, PRINT SCREEN, SHIFT, or BACKSPACE keys to create a keyboard shortcut.

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 scroll 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 clean, smooth surface, such as a mouse 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 menu. 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.

Tip

If you have trouble double-clicking, you can adjust the double-click speed (the amount of time acceptable between clicks). Follow these steps:

1. Open Mouse by clicking the Start button , clicking Control Panel, clicking Hardware, and then clicking Mouse.

2. Click the Buttons tab, and then, under Double-click speed, move the slider to increase or decrease the speed.

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 right-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).

Customizing your mouse

You can change your mouse settings to suit your personal preferences. For example, you can change how fast your mouse pointer moves around the screen, or change the pointer's appearance. If you're left-handed, you can switch the primary button to be the right button.

Tips for using your mouse safely

Holding and moving your mouse properly can help you 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 mouse at elbow level. Your upper arms should fall relaxed at your sides.

• Don't squeeze or grip your mouse tightly. Hold it lightly.


• Move the mouse by pivoting your arm at your elbow. Avoid bending your wrist up, down, or to the sides.

• Use a light touch when clicking a mouse button.

• Keep your fingers relaxed. Don't allow them to hover just above the buttons.

• When you don't need to use the mouse, don't hold it.

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

Types of Mouse

There are different types of mouse devices available in the market. A regular mouse has a rubber or a metal ball on the underside.

The mechanical movement of the mouse device moves the ball. This movement further moves the pointer on the screen. Course: Computer Basics © 2006 Microsoft Corporation, All rights reserved. 20

A trackball is like a regular mouse, but upside down, with the ball on the top. It allows you to have the same control as a mouse in a confined space.

You can use the thumb or the finger to move the trackball to move the pointer.

An optical mouse can be used in the same way as a regular mouse. However, it does not have a ball. It uses a laser to detect movement.

LESSON 1: INTRODUCTION TO COMPUTERS - … 301 – Introduction to Computers & Computing Page 1 LESSON 1: INTRODUCTION TO COMPUTERS LESSON CONTENTS What are Computers About hardware

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