Basics of Computer

Table of Contents

Here we will learn the Basic information's about Computer like its parts, types of devices, classification of Memory, and many more things. If you learn it well then it will complete enough knowledge about computer upto atleast class 8 or Computer Science (ICT) from A to Z.

1.1 What is a Machine?

A machine is anything which makes our work faster and easier whether it is electronic or non-electronic. It is man-made things.

1.2 Development of Computer

In the olden days, there were no computers for calculations. They made many calculating devices some are:-

1.2.1 Abacus

💡Abacus was the first calculating device.

💡 It was invented about 5000 years ago in China and made of wooden frame with poles attached to it.

💡 Used in calculations like addition and subtraction.

1.2.2 Napier’s Bone

💡 Invented by Sir John Napier invented, in 1614.

💡 It was made with a set of rods.

💡 Used in multiplication, division besides, addition and subtraction with this device.

1.2.3 Pascal’s Calculator & Analytical Engine

💡 Pascal’s calculator was the first calculating machine.

💡 It was developed in 1642 by French mathematician and a philosopher Blaise Pascal.

💡 It calculated faster than Napier’s calculation device.

💡 It added and subtracted numbers with a high speed using a series of eight rotation wheels.

1.2.4 ENIAC – (The First Electronic Digital Computer)

💡 ENIAC was the first electronic computer.

💡 Invented in 1942, by University of Pennsylvania by a team led by Professors, J. Presper Eckert and John W. Mauchly.

1.2.5 IBM Mark-I

💡 It was the first electromechanical computer developed in 1943 by Grace Hopper.

💡 It was very big in size.

💡 IBM stands for “International Business Machine”.

1.3 What is a Computer?

Computer :- A computer is an electronic machine that processes and stores the data.

What makes a computer capable?

🔶 Speed :- can do billions of calculations or work as a very high speed.

🔶 Accuracy :- never commits any mistake.

🔶 Diligence :- can performs complicated and repetitive tasks very well, without committing any error and without tired, for log period of time.

🔶 Versality :- can do verity of jobs efficiently depending on the instructions given to it.

🔶 Storage :- can store information or data.

On the basis of thinking process and functions of body parts, a computer system can also divided into two components: Hardware and Software

1.3.1 Parts of a Computer.

Major Parts of a computer are:-

1. CPU (Central Processing Unit)
Brain of the Computer.

2. Monitor
Also known as VDU (Visual Display Unit)

3. Keyboard
A standard keyboard has 104 keys

4. Mouse
Control the arrow in the computer known as cursor.

Parts of the computer are commonly known as devices.

A computer made up of four types of devices:-

§ Input Device

§ Processing Device

§ Output Device

§ Storage Device

1.3.1.1 Input Devices

The devices which help us to input or enter data into the computer are known as Input Devices.

Some input Devices are :-

ü Keyboard
keys or buttons are used to give commands or instructions.

ü Mouse (Pointing Device)
Used to select and point an item on the monitor screen by dragging it on the mouse pad.

ü Joystick
Used to input command while gaming.

ü Microphone (Mike)
Used to feed or input our voice into the computer.

ü Scanner
Device that can copy pictures and pages into our computer.

ü Web camera
Used to take live photos and videos.

1.3.1.2 Processing Devices

CPU (Central Processing Unit) is the processing device. It is also known as the brain of computer. It has ability to process, arrange and save the data in the computer system. It takes input in the form of instruction from the user and gives output.

1.3.1.3 Output Devices

The devices on which we see the result of processing are known as Output Devices.

Some output devices are:-

ü Monitor (VDU)
It looks like a TV screen. Shows the result and shows whatever is typed using the keyboard or is drawn with the help of mouse.

ü Speakers
Part of the computer that let us hear the sound from the programs. Gives the output in the form of an audio.

ü Head Phone
Also used to listen sound but they can be used only by only one person at a time.

ü Printer
Used to print our work on the paper.

§ Some common printers are:-

· Dot Matrix Printer

· Inkjet Printer

· Laser Printer

ü Plotter
Used to print graphical output on paper.

1.3.1.4 Storage Devices or Memory

The devices which are used to store information are called storage devices.

Storage devices or memory units are integral parts of a computer system.

Common Storage devices are:-

ü Hard Disk
Main storage device of a computer system, placed inside the CPU and stores a large amount of information or data.

ü Floppy Disk
Store small amount of information. Inserted in the floppy drive which is fixed inside the CPU.

ü CD (Compact Disk)
Stores much more information than floppy disk. Inserted into a CD drive which is fixed inside the CPU.

ü Pen Drive
A pen drive is a small storage device. It can be easily carried from one place to another.

Memory :- Memory refers to a physical device which is used to store programs or data on a temporary or permanent basis.

There are two types of memories in a computer:-

§ Primary Memory or Main Memory

§ Secondary Memory

1.3.1.4.1 Primary Memory

It is also known as the main memory of the computer. It store the data or information when the computer is in operation.

There are two types of Primary Memories:-

§ RAM (Random Access Memory)
Main working memory of computer.
Situated inside the system unit.
Used for storing inputs, currently running software programs and the result of processing temporarily.
All the stored data would be lost if the computer is turned off.

§ ROM (Read Only Memory)
Also fixed inside the system unit.
It contains some very important instructions that are stored on it at the time of manufacturing.
Help the computer to start up or boot up itself.
Computer can only read information from the ROM, it can’t write anything on it.

1.3.1.4.2 Secondary Memory

Secondary memory stores the data permanently unless it is ensured.

Some secondary storage devices are:-

§ Hard Disk

§ Compact Disk

§ DVD

§ Pen drive

§ Floppy Disc

1.3.2 Types of a Computer

Desktop Computer:- Computers which we keep on desk. Also known as personal computer.

Laptop:- Small Computer which can fit on our lap.

Notebook:- Latest improved model of laptop. Similar to laptop but are lighter in weight.

Palmtop:- Small category of mobile compute which can fit on our palm or carried in our pocket.

Tablet:- Mobile computers with touch screen technology.

1.4 Hardware

Hardware refers to the parts of the computer that you can see and touch. Like- the monitor, the CPU, the Mouse or the Keyboard.

Hardware cannot work by itself it needs step-by-step instructions called Program.

All input, processing, output and storage devices are hardwares.

1.4.1 Monitor

ü This is the most common output device. Connected to the computer to the computer to display the processed information.

ü Pictures are displayed by using a large number of very small dots on screen called pixels.

ü The number of pixels that a monitor can show on its screen is referred to as the resolution of the screen.

ü The commonly used monitor types are:-

· CRT

· LCD

1.4.2 Keyboard

A standard Keyboard has 104 keys.

There are three types of keys on a keyboard:-

§ Alphabetic Keys
There are 26 alphabet keys marked from A to Z.

§ Numeric Keys
There are 10 numeric keys marked from 0 to 9

§ Special Keys

Ø Symbol Keys
Keys which contain special signs and symbols. These special symbols are placed over the numbers on each number key. Shift + Number key = Symbol

Ø Function Keys
There are 12 function keys marked numbered from F1 to F12. Each key perform different function.

Ø Shift Key
Used along with other to perform specific task or functions. Like Typing capital letters, Typing upper symbols, etc.

Ø Alt Key
It also used along with other to perform specific task or function.

Ø Tab Key
Used to move the cursor several spaces forward at once.

Ø Escape Key (Esc)
Used to cancel an ongoing operation.

Ø Caps Lock Key
Used to type Capital Letters.

Ø Enter Key
Use to move the cursor to the next line or to start the new line.

Ø Arrow or Cursor Control Keys
There are 4 Arrow Keys. Used to move the cursor left, right, up or down.

Ø Backspace Key
Erase the texts which is on the left side of the cursor.

Ø Delete Key
Erase the texts which is ahead or right side of the cursor.

Ø Num Lock Key
Allow us to use the numeric pad on the right side of the keyboard.

Ø Spacebar
Used to enter a space at the current cursor location.

1.4.3 Mouse

A mouse is a pointing device attached to a computer to point on the computer.

A mouse generally has two or three buttons.

§ Left Mouse Button

§ Right Mouse Button

§ Middle Mouse Button

Mouse Pad:- A pad, generally of rubber, on which the mouse is kept and moved.

Mouse Pointer :- An arrow head on the computer screen is called the mouse pointer. It moves according to mouse’s movement.

Types of Computer mouse :-

v Wheeled Mouse :- The mouse that has a small wheal instead of the middle button.

v Track Ball Mouse:- The mouse that has ball on its upper side is called Track Ball Mouse.

v Optical Mouse:- The mouse that use light instead of ball for movement is called Optical Mouse.

v Wireless Mouse:- It has sensor and works without wire as remote of television.

How to hold the mouse:-

Hold the mouse lightly so that your palm rests on it.

Put your Index finger on the left mouse button.

Put your middle finger on the right mouse button.

Methods of using the mouse :-

v Single Click
Single clicking means pressing and releasing the mouse button quickly.

Ø Left Click
Used to select an item.

Ø Right Click
Used to open up a list of options of the pointed item.

v Double Click
Pressing and releasing the left mouse button quickly, ‘twice’.
It is used to open the selected item.

v Drag-and-Drop
Used to move an item on the screen or select text on the screen.

1.4.4 CPU

Stands for Central Processing Unit. Controls all the functions of a computer, it is also called the brain of computer.

The CPU consists of three parts:-

§ ALU (Arithmetic and Logic Unit)
This part does all the arithmetic calculations and logical comparisons.

§ CU (Control Unit)
This unit of computer works like a controller of processing.

§ MU (Memory Unit)
It store the data either temporarily or permanently as desired by the user.

1.4.5 Light Pen

A device which can be used to display the menu option and also used or drawing.

1.4.6 Scanner

Scanner is used to insert/capture text and pictures directly into the computer.

1.4.7 Printer

Printer is a device used to produce our output on paper, which is also called hard copy.

Based on the technology used, printers can be classified as:-

§ Impact Printers, and
In this hammer strikes the paper through a ribbon in order to produce output like typewriter.

· Dot-matrix Printers and

· Character Printers

§ Non-impact Printers
In this, printers do not touch the paper while printing, they use chemical, heat or electrical signals to attach the symbols on paper.

· Inkjet Printers,

· Deskjet Printers,

· Laser Printers, and

· Thermal Printers

While talking about printers were refer to two basic qualities associated with printers:-

§ Resolution, and
Print resolution is measured in terms of number of dots per inch (dpi).

§ Speed
Print speed is measured in terms of number of characters printed in a unit of time.
Represented as characters-per-second (cpd), lines-per-minute (lpm), or pages-per-minute (ppm).

1.4.8 Plotter

Plotters are used to print graphical output on paper.

We can get the print of a photograph, drawing, image stored in the computer, by using a plotter.

It is generally used by engineers and architects.

1.4.9 Microphone

1.4.10Joystick

The joystick is a vertical stick which moves the graphic cursor in a direction the stick is moved. Primarily used with video games, training simulators and controlling robots.

1.4.11Speakers

1.4.12UPS

ü UPS stands for Uninterrupted Power Supply.

ü When the main power fails, UPS switches on automatically to supply power to the computer so that it does not turn off immediately.

1.4.13Floppy

1.4.14Hard Disk

It is a device used for storing information. It is the computer’s permanent storage unit.

1.4.15CD/DVD

It is in the shape of a circle. It can store a large amount of information.

1.4.16Bar Code Reader

Bar code readers are used to input data from bar codes.

Bar code is a set of lines of different thicknesses that represent a number.

1.5 Software

Software is the program which can’t be touched or seen and which is used to give step-by-step instruction to perform an action by a hardware. Or

Software is a set of instructions that tells your computer how to perform a particular job.

Software can be classified into two parts:-

§ System Software, and

§ Application Software

1.5.1 System Software

A system software is any computer software which manages and controls computer hardware so that application software can perform a task. It is also called Operating System.

Such as :- Mac OS X, Linux, Windows

Operating System is of two types:-

§ Single User
System operated by a single person on a personal computer.
Ex.- Ms-Dos, Windows7, 8, etc.

§ Multi User
System operated by more than one person through networking.
Ex.- Linux, Unix, etc.

1.5.1.1 Windows

1.5.2 Application Software

Application software is a program that is designed to help the user, to perform specific tasks.

Such as:- Calculator, MS-Paint, MS Excel, Wordpad, etc.

1.5.2.1 Microsoft Office

Microsoft is a company who develop many applications such as :-

1.5.2.2 MS-Paint

1.5.2.3 WordPad

1.6 Internet

1.6.1 What is Internet?

Internet is a huge network of computers, where computer all over the world can share information with each other. It is the fastest means of communication.

1.6.2 History of Internet

Ø In 1969, the Department of Department of Defense in US founded a network called ARPANET.

Ø This was regarded to be the first step forward the creation of internet.

Ø Internet, however came to be used more widely in the 1990’s.

1.6.3 Computer Network

When a computer is connected with another computer with the help of wires, it is said to be computer network.

1.6.3.1 Requirements for an Internet Connections

Ø Computer

Ø Modem

Ø Web Camera

Ø Telephone or Cable line

Ø Operating system which support internet

1.6.4 Internet Terms

1.6.4.1 WWW

Ø WWW stands for World Wide Web.

Ø It is collection of Interconnected Pages that contain text, pictures, audio and movies.

Ø World Wide Web is popularly known as the Web or W3.

Ø We can access these pages by using a program called web browser.

1.6.4.2 Website

Website is a collection of web pages, images, videos and multimedia files, which provide information in the form of a book.

1.6.4.3 Web Page

A web page is loaded when you type the web address in a web browser. A web page may contain many types of information in the form of text, image, graphics, animation and sound.

1.6.4.4 Web Browser

A software or program that is used to get the information from different websites.

Such as:-

Microsoft Internet Explorer, Mozilla Firefox, Opera, Google Chrome, etc.

1.6.4.5 Home Page

The main page or the first page which appears when your open a website is called Home Page.

Hyperlinks

1.6.4.6 URL

The address of a website or webpage is called the URL.

Ø URL is stands for Uniform Resource Locator

Ø URL is the unique address of a website on the internet.
Ex.- http://www.worldkids.net

1.7 Other Important Points

v Charles Babbage called as the “Father of Computer”.

v Alan Tuning was conceived in Chhattarpur, Orissa, India. He is called the “Father of Computer Science”. His father Julius Muthison Tuning was a member of the India Civil Service.

v Blaise Pascal, French mathematician, physicist and religious philosopher called the “Father of Programming Language”.

v Vinton Gray Cerf is called the “Father of the Internet”.

v Charles Babbage the famous mathematician, philosopher, mechanical engineer originated the concept of a programmable computer.

Ø In 1822, he designed his Difference Engine and,

Ø In 1833, he designed Analytical Engine which has the basic components of modern Computer.

v The history of CRT (Cathode Ray Tube) can be followed back to (at least) 1854, when the skilled German glassblower and mechanic Heinrich Geissler (GeiBler) (1814-1879) was asked by the professor of Mathematics and physics in Universität Bonn (University of Bonn) Julius Plücker (1801 – 1868) to design an apparatus for evacuating a glass tube.

v Ada Lovelace, English Mathematician, she is sometimes considered the world’s first computer programmer.

v The world’s first Personal Computer called Apple II, was made in 1977.

v Microsoft is an American company. It develops computer software and hardware parts.

v Douglas Engelbart created the first computer mouse in the year 1964 and was made up of wood.

v Abacus was the first calculating device which was invented about 3000 years ago it still in use.

v Tom Kilburn invented the first software in 1948 at the University of Manchester in England.

v Steven Paul “steve” was an American, designer and inventor. He is best known as the co-founder, chairman, and chief executive officer of Apple.

v William Henry “Bill Gates III” (born October 28, 1955) is an American business magnate computer programmer and philanthropist. Gates is the former chief executive and former chairman of Microsoft.

v In 1989, Tim Berners-Lee invented the World Wide Web (www), an internet based Hypermedia initiative for global information sharing. Also known as the founder of www.

v The word computer has came from the word compute, which means to calculate or workout something. Initially, computers were used for the purpose of calculation. That is why it is called THE COMPUTER.

v If invalid data is entered in a computer program, the resulting output will also be invalid. This term is known as GIGO “Garbage in, Garbage out”.

v The scroll wheel was invented at Microsoft in 1993 by Eric Michelman.

v 12 August 1981, marks the birth of IBM-Pc, the computer that changed the world.

v An operating system is a software program that enables the computer hardware to communicate software.

v The first theory of software was proposed by Alan Tuning in 1935.

v All the input and output devices constitute the hardware while the task of solving the sum or processing is done by the software. So a software supports the process part of the IPO cycle (Input-Process-Output cycle)

v Sir Christopher Lattam Sholes invented the Qwerty keyboard.

v Charles Simonyi (September, 1948) is a Hungarian American Computer software executive who over saw the creation of Microsoft’s flag ship office suite of applications.

v Robert Gaskins is the first person who gave the idea for the name of “PowerPoint” due to problem with trademarks.

v The first e-mails was sent by Ray Tomilinson in 1971.

v Netcape Navigator was the world’s first powerful browser.

Basics of Computer | Introduction to ICT | Basic components of Computer