Home / Introduction to computers

Introduction to computers

INTRODUCTION TO COMPUTERS

Computer literacy is having an understanding of what a computer is and how it can be used as a resource.   Literacy, which refers to having knowledge and understanding, needs to be distinguished from computer competency, which refers to having a skill.
Computer competency is applying your skill with computers to
meet your information needs and improve your productivity.
Computer competency also means being able to transfer basic
skills to new systems and new software.

Definition of a computer

A computer may be defined as an electronic machine that processes data to generate information with speed and accuracy.

A computer can also be defined as an electronic device that accepts data and

instructions, stores them temporarily in its memory awaiting processing, automatically
executes/obeys the set of the issued instructions to produce information from the input raw data.

How to Start Up a Computer
Starting up a computer is commonly referred to as booting. It is a process that a
computer undergoes before it is ready for use once it is switched on.
The standard procedure of booting is as follows:
-Ensure there is power from the mains. Switch on the System unit, then switch
on the monitor
-Wait for instructions on the screen e.g some computers will require you to
Press (Fl) key to continue.
Booting is of two kinds; cold booting and warm booting.
Cold booting: It is the first time a computer is switched on.
I.e. if the computer was initially off.
Warm booting: Refers to the process of resetting or restarting a computer that
has been running for some time. We restart computers if there is a minor
technical hitch such as hanging.
Shutting down a Computer

  • Close all programs if there is any that is open.
  • Click Start>Shutdown(Turn off Computer)
  • In the dialog Box Select shut Down (Turn Off).
  • After the system unit goes off Switch off the monitor.
  • You can also do the following;
    Press Alt key together with F4. I.e. Alt+F4.
  • From the options displayed on the screen on a window such as the one below
    click Turn Off or press U.

COMPUTER BASED INFORMATION SYSTEM

A computer is a device made up of a combination of electronic and electromechanical (part electronic, part mechanical) components. By itself a computer has no intelligence and is referred to as hardware, which means simply the physical equipment. The
hardware can’t be used until it is connected to other elements, all of which constitute the six parts of a computer-based information system.

The following are the components that makeup a computer- based information system.

A computer based information system combines six elements: hardware, software, data/information, procedures, people, and communication/connectivity

Hardware

This is the physical or the tangible parts of a computer e.g. the keyboard, mouse, monitor, system unit, printers etc.

Software

Software is the term used to describe the instructions that tell the computer hardware how to perform a task.

Data/Information

Data is the raw material, whether in paper, electronic or other form – which is processed
by the computer.   In other words, data consists of the raw facts and figures that are
processed into information.   Information is summarized data or otherwise manipulated
(processed) data.   For example the raw data of employees’ hours worked and wage
rates is processed by a computer into the information of paychecks and payrolls.

People

People constitute the most important component of the computer system.   People

operate the computer hardware, they create and use the computer software, they enter the data, and use the information the system generates.

Procedures

Procedures are descriptions of how things are done, steps for accomplishing a result. Procedures for a computer system appear in documentation manuals, also known as reference manuals and user guides, which contain instructions, rules and guidelines to follow when using hardware and software.

Communication

Communication also called connectivity is when one computer system is setup to share data and information electronically with another computer system. Such connections may be through telephone lines, cables, microwave transmissions etc.

DIGITAL BASICS OF A COMPUTER

Computers may seem incredibly complicated devices, but their underlying principle is

simple. When you open up a microcomputer, what you see is mainly electronic circuitry. And what is the most basic statement that can be made about electricity? It is simply this: It can be either turned on or turned off.

In a two-state on/off arrangement, one state can represent a 1 digit, the other a 0 digit.
Because computers are based on on/off or other two-state conditions, they use the
binary number system, which consists of only two digits – 0 and 1. In the binary system,
each 0 and 1 is called a bit   short for binary digit. In turn, bits can be grouped in
various combination represent characters of data-numbers, letters, punctuation marks,
and so on. for example, the letter H could corresponds to the electronic signal
01001000. In computing, a group of 8 bits is called a byte, and each character is
represented by 1 byte.

Digital signal represented by 0s and 1s

Computers use digitally coded information to process, and store data and to communicate with one another.

Advantages of using computers

i.)         Computers operate at a high speed.

ii.)        The computer results are very accurate.

iii.)       Computers can work continuously without getting tired or bored.

iv.)       Computers can work on voluminous data items.

v.)        Computers can solve any problem, provided the relevant instruction

set/programs is input.

vi.)       Computers can operate in risky environment environments e.g. volcanic sites,

lethal chemical plants, where human life is feared.

vii.)      The computer is flexible and can adapt to any work load without much strain.

viii.)     Computers produce reliable information.

ix.)       Large volumes of data can be conveniently stored, assessed and altered.

x.)        Computers can provide useful information to management for control and

decision making.

xi.)       Computers help to reduce paper work significantly.

xii.)      The number of persons required for performing various organizational

activities will be reduced by using computers.

xiii.)     The use of computers for office activities reduces the requirement of office

space which otherwise is required.

Disadvantages of computers

i.)         Computers are costly

ii.)        Due to rapid change in computer technology, the computer and related

facilities can become outdated very fast.

iii.)       There is usually the fear that installing computers into an organization might

result in replacing human employees.

iv.)       Important data may be lost incase of virus attack or machine breakdown.

v.)        Company data may be at risk of illegal copying and unauthorized by hackers.

THE EVOLUTION OF COMPUTERS

Computers have developed through four so-called generations, or stages, each one
characterized by smaller size, more power and less expense than its predecessor.

First Generation (1944-1958)

The first large-scale electronic computer, the grandparent of today’s handheld machines
was the Electronic Numerical Integrator and Computer (ENIAC), which operation in
1946. This computer weighed 30 tons and occupied about 1800 square feet of floor
space.

They were characterized by vacuum tubes which failed oftenly, they were slow,

produced tremendous amount of heat and were very large compared to microcomputers
used today. ENIAC and UNIVAC I – UNIVersal Automatic Computer,   which was used
by the U.S. Bureau of the Census from 1951 to 1963 – are examples of First Generation
Computers.

ENIAC was the first large-scale electronic computer, it weighed 30 tons, filled 1800 sq feet, included

18,000 vacuum tubes and it failed about every 7 Min.

Second Generation (1959-1963)

By the early 1960’s, transistors were used in circuitry. (A transistor is an electronic
switch that alternately allows or does not allow electronic signal to pass) Removable
magnetic disks were introduced as storage devices. Second Generation computers
tended to be smaller, more reliable, and significantly faster than First Generation
computers.

Third Generation (1964-1970)

In the third period, the integrated circuit (IC) – A complete electronic circuit that

packages transistors and other electronic components on small silicon chip – replaced traditional transistorized circuitry.

The use of magnetic disks for secondary data storage became widespread, and

computers began to support such capabilities as multiprogramming (running more than one program at a time) and time sharing (people using the same computer
simultaneously)

Fourth Generation (1971-Now)

Large-scale Integrated (LSI) and Very-Large-Scale integrated (VSLI) circuits were

developed that contained hundreds to millions of transistors on a tiny chip. The

microprocessor and VSLI circuit technology caused radical changes in computers – in
their size, appearance, cost, availability, and capability – and they started the process of
miniaturization:-the development of smaller and smaller computers.
Also during this time, computers main memory capacity increased, and its cost
decreased, which directly affected the types and usefulness of software that could be
used. Software application like Word Processing, Electronic Spreadsheets, Database
Management programs, Painting and Drawing programs, Desktop Publishing and so
forth became commercially available giving more people reasons to use computers.

TYPES OF COMPUTERS

Other than microcomputers, computers still come in a variety of sizes and with a variety of processing capabilities. We can categorize them as follows;

i.) Supercomputers

ii.) Mainframe computers
iii.) Workstations

iv.) Microcomputers

v.) Microcontrollers

 

It’s hard to give a precise definition to each since computer speeds and storage
capacities change rapidly. Nevertheless, the following definitions will suffice;

Supercomputers

First developed in 1970s, they are the fastest and highest-capacity computers. They

may occupy special air-conditioned rooms and are often used for research. Among their
uses are worldwide weather forecasting and analysis of weather phenomena, oil
exploration, aircraft design, prediction of spreads of epidemics, and mathematical

research. Unlike microcomputers, which generally have one processing unit, super computers have hundreds to thousands of processors and can perform trillions of calculations per second.

A supercomputer may be made up of many cabinet like units working together.

Mainframe computers

The only type of computers available until the late 1960’s, mainframe computers are
less powerful than supercomputers, but they are still fast, mid to large-size capacity
machines. Their size varies depending on how many concurrent users they are serving – from few   hundreds to thousands of people. Mainframes are used by many banks,
airlines, insurance companies, mail-order houses, universities etc. Mainframes also
have many processors.

mainframe computers have many process and can work really fast

Workstations

Workstations introduced in early 1980’s are expensive powerful desktop computers

used mainly by engineers, scientists and special-effect creators for sophisticated

purposes. Providing many capabilities comparable to midsize mainframes. Workstations are often connected to a larger computer system to facilitate transfer of data and

rmation. Workstations are used for such tasks as designing airplane fuselages, prescription drugs, and movies’ special effects.

Microcomputers

Microcomputers, also called personal computers (PCs) are small computers that can fit
next to a desk or a desktop, or can be carried around. Some microcomputers called
tower units are higher than they are wide. whether desktop, tower, notebook, palmtop,
electronic organizer, or pen-based, personal computers are now found in most
businesses.

Microcontrollers

They are also called embedded, dedicated or hidden computers, microcontrollers are tiny computers installed in “smart” appliances like microwave ovens and pocket
calculators. They are dedicated to performing a restricted number of tasks.

COMPUTER HARDWARE

As mentioned earlier, computer hardware is the physical or the tangible parts of the computer. Computer hardware is categorized depending on which of the five computer operation it performs;

i.) Input

ii.) Processing and memory
iii.) Output

iv.) Storage

v.) Communication

some basic computer hardware

Devices that are connected to the computer and are controlled by the computer are

referred to as peripheral devices. These devices can be external, such as keyboards, mice, monitors, and printers or internal (inside the computer system unit) such as a floppy disk, harddisk, modem etc.

Input hardware

The function of input hardware is to accept data and covert it into a form suitable for

computer processing. In other words, input hardware allows people to put data into the computer in a form that the computer can use.

i.)    Keyboard: A keyboard includes the standard typewriter keys plus a number

of specialized keys. The standard keys are used mostly to enter words and

numbers.

ii.)   Mouse: A mouse is a device that is rolled about on a desktop to direct a

pointer on the computer display screen. The pointer is a symbol usually an

arrow, that is used to select items from lists (menus) or to position the cursor.
The cursor also called an insertion point, is the symbol on the screen that
shows where data may be entered next, such as text in a document.
iii.) Scanners, are often used in desktop publishing, translate images and text,
drawings and photos into digital form. The digital images can then be

processed by the computer, displayed on a monitor, inserted in documents, stored in a storage device or transmitted to another computer. Scanners convert images into a digital format.

iv.)  Tracker ball: A tracker ball is a movable ball on top of a stationery device,

the ball is rotated with the finger or the palm. In fact, a tracker ball looks like an upside down mouse.

v.)   Joystick: A joystick is a pointing device that consists of a vertical handle like

a gearshift lever mounted on a base with one or two buttons. Joysticks are used mainly in video games, in some computer aided design systems, and computerized robot systems.

vi.)  Touchpads: A touchpad is a flat rectangular device that uses a weak

electrical field to sense your touch. Touchpads let you control the

cursor/pointer with your finger, the cursor follows the movement of your

fingertip. You click by tapping the pad or pressing buttons adjacent to the pad.
Some portable computers used the touchpad to input data and commands.

Figure 13: A touch pad is moustly found on laptop computers.

vii.)   Light pen: A light pen is a light sensitive pen like device that is connected to

a computer terminal by a wire. Graphic designers, engineers and illustrators use light pens.

Light pen

viii.)  Bar-code readers – Bar code readers are photoelectric devices that convert

barcode strips into digital code. Barcodes are vertical zebra-stripped marks you see on most manufactured retail products.

ix.)  Microphone: The microphone converts human speech into digital code. an

audio input device records or plays analog sound and translates it for digital storage and processing.

x.)  Digital camera: A digital camera uses a light sensitive processor chip to

capture photographic images in digital form on a memory card inserted on the

camera.

xi.)  Other input devices include; Touch screen, Digital tablet, Fax machines,

Mark-and-Character recognition devices, Automated teller machines (ATM)

etc.

The five categories of computer hardware are input, processing and memory, output, storage and communication.

PROCESSING AND MEMORY (PRIMARY STORAGE) HARDWARE

The computers control center is made up of the processing and main memory devices, the system unit houses that part of electronic circuitry that does the actual and the
memory that support the processing. Together these components are referred to as processing hardware.

CPU – the processor: The Central Processing Unit is the processor or the computing part of the computer. It controls and manipulates data to produce useful information. In a microcomputer the CPU is an approximately 1.5-inch (3.75-cm) square chip called a microprocessor, with electrical circuit printed on it. This microprocessor and other
components that make it work are mounted on the main circuit board called the
motherboard or the system board.

CPU is the central processing chip

Primary memory – Working storage: Primary memory also called the main memory or

the RAM (Random Access Memory)   is the temporary storage where data and

programs needed for immediate processing are held. Computer memory is contained on memory chips mounted on the motherboard.

RAM is a temporary storage area that stores information that is currently being processed by the
CPU.

The major characteristics of the main memory are;

i.) It has a quick response time

ii.) It is volatile i.e. all the information stored in it is lost when power is turned off.

OUTPUT HARDWARE

The function of output hardware is to provide the user with the means to view and use information produced by the computer system. Information is output either in hardcopy output (Information printed on paper) or soft copy output (information displayed on your computer monitor).

Monitor / Visual Display Unit VDU

The monitor is a television like screen on which you can read text and graphics.

Monitors have knobs or buttons that adjust brightness contrast and positioning of the display screen.

TFT and CRT monitors

Types of monitors

Cathode-Ray Tubes (CRTs)

This is the same technology used on TV sets and involves the use of a vacuum tube. The CRT’s screen display is made up of small dots called pixels. A pixel is the smallest unit on the screen that can be turned on or off or made into different shades.

Liquid Crystal Display (LCD)

This is a flat panel display that consists of a substance called liquid crystal whose

molecules lineup in a particular way. Under an applied voltage the molecular alignment
is disturbed, which changes the optical properties of the liquid crystal in the affected
area.

Printer

A printer is an output device that prints characters, symbols, and graphics on paper

(The printed out put is generally referred to hardcopy since it is relatively in a permanent
form)

Categories of printers

Impact printers

Impact printers have mechanism resembling that of a typewriter, it forms characters or images by striking against an inked ribbon leaving an image on paper. The dot-matrix printer is a good example of impact printer, they are noisy, inexpensive and can print on several layers of paper at the same time.

Non-impact printers

Non-impact printers are used almost everywhere now, they are fast and quieter than impact printers.

The two types of non-impact printers often used with microcomputers are laser printers and ink-jet printers.

Laser printers: – Like dot-matrix printer a laser printer creates image with dots.

However, as in a photocopying machine, these images are created on a drum, treated
with magnetically charged ink like toner (powder) and then transferred from the drum to the paper.

Ink-jet printers: – Inkjet printers spray small, electrically charged droplets of ink from four nozzles through holes in a matrix at high speed onto paper. They are less
expensive than laser printers but print at a slower speed.

An inkjet printer

Plotters

A plotter is a specialized output device designed to produce high-quality graphics in a variety of colours. Plotters are used for creating large hardcopy items, such as maps, architectural drawings, and 3D illustrations. Such items are usually too large to be printed on regular printers.

Speakers and headphones

This are devices that synthesis sound output. They are basically used with a computer having multimedia capabilities e.g. you can listen to music and sounds from your
computer using either the speakers or the headphones.

SECONDARY STORAGE HARDWARE

Secondary storage stores computer software and data in a form that is relatively

permanent, or nonvolatile i.e. the data is not lost when power goes off. For any

information in the secondary storage to be processed it must first be transferred to the RAM.

RAM losses all the data when power goes off, but secondary storage retains data even in the absence of power, that’s why its important to save your work in a secondary
storage device such as a diskette or the hard disk before shutting down your computer. The process of retrieving data from a storage device is referred to a reading while that of copying information into a storage device is called writing.

HARD DISKS

Hard disks are thin   but rigid metal or glass platters covered with a substance that

allows data to be held in form of magnetized spots. Hard disks are also sealed within an enclosed unit to prevent any foreign matter such as dust, smoke etc. from getting inside. Data may be recorded on both sides of the platter.

The hard disk is sealed and enclosed in the system unit.

The platters spin at a very high speed on the drive spindle, while the read/write heads read and write information and data on the disk surface.

Computer software and data is basically stored on the computer hard disks since they have larger   capacity compared to floppy disks.

OPTICAL DISKS

An optical disk is a removable disk on which data is written and read through the use of laser beams; a high power laser beam is used to represent data by burning tiny pits into the surface of a hard plastic disk. To read the data, a low-powered laser light scans the disk surface: pitted areas are not reflected and are interpreted as 0 bits; smooth areas are reflected and are interpreted as 1 bit.

Figure 25: Data on optical disks is written using a strong laser beam and read using a weaker laser beam.

Categories of optical disks

CD – ROM disks – Compact Disk-Read Only Memory   are the commonly used optical disks, Read only means that once information has been written on the disk it cannot be changed. They are mainly used in storage of computer programs, music, movies and other data files. These disks are inserted in a CD-ROM drive.

CD-R – Compact Disk-Recordable is a CD format that allows users with a CD writer/
CD-R drive to write data only once onto a new blank CD. Once data is written it cannot
be changed. A special CD writing software may be necessary when writing to a CD. e.g.
Nero Burn

CD-RW Disks – Compact disks rewritable, are disks that allow the user to write and rewrite data on the CD i.e. the disk can be used over and over again.
DVD/DVD ROM – This is a silvery, 5-inch optically readable digital disk that looks like an audio compact disk but can store over 17 gigabytes, allowing greater data storage, studio guilty video images, and theater-like surround sound.

Advantages of DVDs

i.)         They have large storage capacity and a fast data transfer rate.

ii.)        Better audio quality

iii.)       They offer a better picture quality and video.

iv.)       They are available in both Recordable and rewritable capabilities.

Flash disk

They consist of a circuitry that is enclosed in a plastic or metal casing, they are usually
connected to the computer using the USB port. Flash disks are small and convenient
since the can carry lots of data. They are mainly used in transferring information from

one computer to another they come in different capacities e.g. 32MB, 62MB, 128Mb, 256MB, 512MB, 1GB, 2GB and above.

Flash disks are very convenient due to their small size.

Tape storage

Magnetic tape is a thin plastic tape that has been magnetically coated for storing data as magnetic spots. They are primarily used for backing up and archiving data. They are slightly smaller than the music cassettes. They can store large quantities of data raging from 10 GB to 70 GB. They are used with the tape drive.

KEYBOARDING TECHNIQUES

The computer keyboard is the basic input device that converts letters, numbers and
other characters into electrical signals that are machine-readable. The keyboard
resemble the typical typewriter but has additional keys that perform some specialized
functions.

The keyboard is the primary input device, the figure above shows the common layout of a keyboard.

Standard typing keys

Typing keys are the familiar QWERTY arrangement of letters, numbers and punctuation keys found on any typewriter. QWERTY refers to the alphabet keys in the top left row on a standard typewriter keyboard.

Cursor movement keys

The cursor also called the insertion point, is the symbol on the display screen that

shows where data may be entered next. The cursor-movement keys, or arrow keys, are used to move the cursor around the text on the screen. These keys move the cursor
left, right, up, or down. The keys labeled PgUp stands for Page Up, and the key labeled PgDn stands for Page Down. These keys move the cursor the equivalent of one page or one screen at a time up (towards the beginning of the document) or down (towards the
end of the document).

Numeric Keys

On a standard 101/102 key board, a separate set of keys, 0 through 9 known as the
numeric keypad, is laid out like the keys on a calculator. The numeric keypad has two purposes;

i.)         When the Num Lock key is on the keys may be used to manipulate numbers as

on a calculator.

ii.)        When the Num Lock key is off the numeric keys may be used as cursor

movement   keys.

Function Keys

The function keys are labeled with an F and a number, such as F1 and F2. They are
used for issuing commands not typing in characters. The purpose of each function key
is defined by the software you are using. For example in one program pressing F2 may
print   your document while in another program it may save the document to the disk.
Desktop microcomputers basically have 12 function keys while portable computers have

Special keyboard keys

Enter key – You can press the Enter to tell the computer to carry out a task. In a word processing this key starts a new paragraph.

Backspace key – You can press Backspace to erase the character to the left of the cursor.

Delete key – You can press Delete to erase the character to the right of the cursor.

Num Lock key – You can switch it on to enter numerical data and perform calculations, You can switch it off to use the numeric keys as cursor movement keys.
Application key –   You can press the Application key to quickly get a shortcut menu for an item on your screen.

Spacebar – You can press the Spacebar to insert a blank space.

Windows key – You can press the Windows key to quickly display the Start menu when working in a windows operating system.

Ctrl key – You can use the Ctrl key in combination with another key to perform a

specific task e.g. Ctrl+C = Copy, Ctrl + X = Cut, Ctrl + V = Paste, Ctrl + P = Print etc.
Alt key – This is also a combination key and has to be combined with other keys to
perform a task e.g. Alt + Ctrl + Del to restart the computer, Alt + F4 to exit from a
window.

Shift key – This a combination key that produces the uppercase/capital letter of a character, it is also used when typing in special character such as
!@#$%^&*()_+|}{“:>?<.

Caps Lock Key – This key lets you enter text in uppercase or lower case, it has an

indicator light at the top right side of the keyboard; when the light is on   typed characters appear in upper case.

Escape key – You can press the Esc key to quit a task you are performing or when exiting from a menu selection.

Num Lock key – This key switches the numbers in the numeric key pad on or off.

When it is on you can type in numbers and perform calculations, when off the numeric key pad acts as cursor movement keys.

Computer ergonomics

Ergonomics is the study of physical relationships between people and their work

environment. Keyboard manufacturers as result of ergonomic studies have developed ergonomically sound keyboards to help prevent injuries to the computer users.

MOUSE TECHNIQUES

The mouse is a pointing device that is rolled on the desk surface, to direct a pointer on the computer screen.   The mouse pointer is the symbol that indicates the position of the mouse on the display screen. The pointer changes from an arrow to an I-beam
depending on the task that you are currently performing.

If you click the mouse button when the I-beam is positioned within text, a cursor which is a blinking vertical line appears, the cursor indicated where text will appear when typed. Different kinds of mouse come in different colours and shapes, some may have two to four buttons or even a wheel. They are usually connected to the computer motherboard using a cable but we also have wireless/cordless ones which are battery powered and use a receiver hooked on the motherboard.

Some brands of mouse such as the Microsoft intellimouse, have a wheel between the
left and right mouse button with which one can scroll through the contents of a file.

Mouse operation      Description

Point                           Move the pointer to the desired spot on the screen, such as

over a button or a word

Click                           Press and release the left mouse button once. A click often

selects an item on the screen.

Double-click              Press and release the left mouse button twice in rapid

successions. A double click will open a document or program.

Drag                            Press and hold the left mouse button while moving to a

different location.

Drop                            Release the mouse button after dragging. Dragging and

dropping is and easy way of moving items on the screen.

Right-click                 Press and release the right mouse button once, in windows

programs, this brings up a pop-up menu with options for the clicked item.

Triple-click                 Press the left mouse button thrice in rapid successions; in a

word processor this will select an entire paragraph.

Right-drag                 Drag with the right mouse button, right dragging an item will

prompt you to copy, move or create a shortcut.

Marquee-select         Dragging the left mouse button within a given range,

marquee select is used for multiple selection of items.

Note: If you are left-handed, you can switch the functions of the left and right mouse buttons to make the mouse easier to use.

 

COMPUTER NETWORKS

A computer network is an interconnection of two or more computers to facilitate

exchange of information and sharing of expensive equipment such as printers, fax machines etc.

Types of computer networks

Wide Area Network (WAN)

A wide area network is a communication network that connects computers within a large geographical area, such as a state or country.

Metropolitan Area Network (MAN)

A metropolitan area network is a communication network that connects computers within geographic area the size of a city or suburb.

Local Area Network (LAN)

A local area network is a privately owned communication network connecting computers within a small geographic area, perhaps an office, within a building, or buildings close to each others such as a college campus.

COMPUTER SOFTWARE

Definition: Computer software is the logic that guides the computer hardware when performing a task.

A computer has not intelligence of its own and must be supplied with instructions that tell it what to do and how to do it. Software is made up of groups of related programs written in a specific code called a programming language and based on the computers language of 0s and   1s. Software acquired to perform a general business function is called a software package. Software are generally created by professional software programmers and come in CD-ROM, Disk, or online.

 

Software can generally be grouped into

1.) System software

2.) Application software

System software

System software is software designed to   allow the computer to manage its own

resources and run the hardware and basic operations. It lets the CPU communicate with the keyboard, the screen, the printer and the disk drive.

Examples of Operating Systems include, DOS and Windows 3x , Windows 95/98,
Windows NT/2000, Window XP, OS/2 Warp, UNIX, Linux, Mac OS, Netware etc.

Functions of the operating system

  1. Memory allocation and loading of programs
  2. It manages the computer resources
  3. It performs input output controls
  4. Provides scheduling and accounting

Application software

Application software is the software that is designed to meet the users specific needs. It
performs tasks to directly benefit the user and increase their productivity and creativity.

Applications software come in four categories;

1.) Basic productivity software – Most of the common applications software

packages used today are productivity software, their purpose is the make the

user more productive when performing general tasks e.g. Word-processing,

spreadsheets, personal finance, presentation graphics, database managements, integrated and web browsing applications.

2.) Specialty tools – This is software designed for application is particular

occupation and businesses. examples include, desktop publishing, project

management, Computer Aided Designing and Computer Aided Manufacturing (CAD/CAM) drawing and painting, multimedia authoring software etc.

3.) Entertainment software – this includes computer games.

4.) Educational reference software – This are electronic research and training

materials e.g. Encyclopedias, Phone books, Library searches, bible software etc.

 

Productivity software

Word processing

Word processing software allows you to use computers to create, edit, store and print
documents. you can easily insert, delete, and move words, sentences and paragraphs.
Examples of word-processing programs include, Microsoft word, Word perfect etc.

Spreadsheet software

An electronic spreadsheet is grid of columns and rows that allows the users to enter

details and financial schedules and later perform calculations on the entered data. A

spreadsheet document is called a worksheet, and several worksheets make up a

workbook. Examples of spreadsheet programs include, Microsoft Excel and Lotus 1-2-3

Database Management system software

A database is a collection of data stored electronically in a computer system. Database management system is a program that controls the structure of a database and access to the data. Today the principal database programs are Microsoft Access, FoxPro,
Oracle, Claris Filemaker Pro. etc.

Personal finance software

Personal finance software lets you keep track of income and expenses, write checks,
and plan financial goals. Examples include Quicken, Microsoft Money, Win Check etc.

Group ware

Groupware is software that is used on a network and serves a group of users working together on the same project. Groupware improves productivity by keeping members continually aware of what their colleagues thinking and doing. Examples include Lotus note and MS outlook.

Review Questions

Top