Touchpad Plus Ver. 3.1 Class 5: Linux & LibreOffice

1 FUNDAMENTALS OF A COMPUTER

A computer is an electronic device which accepts data given by the user, i.e., input. It then processes the data according to the given instructions and finally produces the result as output.

Data and Information

Data is any collection of numbers, characters or other symbols that has been coded into a format that can be input into a computer and processed. Data on its own has no meaning. In other words, data can be defined as a representation of facts, concepts, or instructions collected for analysis. It is only after processing by a computer that data becomes information.

The main types of data that can be input into a computer are numeric, text, date, graphics and sound. Data is stored as a series of numbers inside the computer.

Characteristics of A Computer

Speed: Computer can process millions of instructions in seconds. Same calculation that would have taken hours and day to complete can be completed in a few seconds using the computer. The speed of computer is calculated in terms of MIPS (Millions of Instructions Per Second).

Accuracy: A computer provides a high degree of accuracy. Every calculation is performed with the same accuracy.

Diligence: Computer can work for hours without any break or boredom. It does not get tired.

Storage capacity: Computer can store very large amount of data. You have many storage devices like CD, DVD, flash drive, etc. to store your data.

Versatility: Computers can be used to perform different types of tasks. At one point of time, you can type a document, the next moment you can listen to a song or watch a video.

Compactness: With regular advancements in technology, the computer size is decreasing.

Reliability: Computer does not make mistakes. If the input is correct, then the computer always gives the relevant answer to the input.

Power of remembering: The data stored in the computer can be recalled at any time

Limitations of a computer

Computer is a versatile machine and performs multiple functions, but it has the following limitations:

Lack of decision-making ability: A computer does not have a brain like human beings. It cannot take a decision on its own. It can only perform the tasks that are instructed by the human being.

Lack of intelligence: A computer is not gifted with intelligence as human beings are. It can only work as per the instructions given by human beings.

Lack of feelings and emotions: Computers are different from human beings. It does not possess feelings and emotions like human beings. It cannot do anything on its own.

Time taken in planning and programming: We have to first choose the jobs to be computerised, and then proper planning and development of programs can take days, months and sometimes even years.

Working of a computer

A commonly used computer needs the following hardware to work:

Input devices

Output devices

Storage devices

CPU (Processing device)

Along with the hardware, the computer requires software to work. A set of instructions written in any computer language is known as a program. Programs are stored in the computer’s memory.

IPO Cycle

A Computer takes the data as input, processes and then gives result as an output.

IPO Cycle

Input Devices

A computer accepts data and instructions from you through input devices. Data can be in the form of numbers, text, sound or graphics. Some of the input devices are:

Keyboard

Keyboard

A computer keyboard is the main input device for computers. You can press the keys on it to input data in the form of words and numbers.

A standard keyboard has 104 keys, which can be classified as follows:

Alphanumeric keys (A–Z, a–z, 0–9)

Control keys (Ctrl, Alt, Esc, etc.)

Function keys (F1–F12)

Special keys (Caps Lock, Backspace, Spacebar, Arrow keys, Home, End, etc.)

Punctuation keys (, , -, ;, etc.)

Mouse

Mouse

It is a pointing device that allows you to put data into a computer by using the point, click and drag and drop commands. It controls the movement of the pointer on the screen. It is used to move and select icons, files and folders on your computer. It can also be used to draw pictures.

Scanner

Scanner

Scanner is a device that helps to input printed pictures and text into the computer by reading them. Different types of scanners are available. The choice of scanners depends on the purpose for which these are to be used. Some popular types of scanners are:

Hand-Held Scanner

Hand-Held Scanner: It is a type of scanner that is held in hand and rolled over a flat image or document. It is used to scan documents into their digital forms.

Flatbed Scanner

Flatbed Scanner: It is a type of scanner that uses a flat, glass surface for scanning documents. It looks like a photostat machine.

Sheetfed Scanner

Sheetfed Scanner: It is a type of scanner that allows multiple papers to be scanned at a time. In this scanner, the stack of papers is kept on top and the scanner automatically scans the pages one by one. It is widely used in offices to scan documents.

Webcam

Webcam

It is a digital video camera connected to a computer. It helps to put your image into the computer when you are connected to the Internet.

Graphic Tablet

Graphic tablet

It allows to directly draw on a computer screen. The device consists of a flat surface upon which you can draw with an attached stylus which looks like a pen.

Joystick

Joystick

Joystick is a pointing device which is used to control the movement of a pointer on your computer screen. It is mostly used device to play games on the computer.

Microphone

Microphone

It is an input device that is used to record voice, music and sound into the computer system.

Touchscreen

Touchscreen

A touchscreen is a screen sensitive to touch. We can interact with a computer by touching areas on the screen. Tablets, smartphones, ATMs have