Introduction to Computer

                             

A computer is an electronic machine, operating under the control of instructions stored in its own memory that can accept data, manipulate the data according to specified rules, produce results, and store the results for future use. Computers process data to create information. 

Data is a collection of raw unprocessed facts, figures, and symbols. 

Information is data that is organized, meaningful, and useful. To process data into information, a computer uses hardware and software. 

Hardware is the electric, electronic, and mechanical equipment that makes up a computer. 

Software is the series of instructions that tells the hardware how to perform tasks.

There are two categories of computer software: system software and application software. 

System software consists of the programs that control the operations of a computer and its devices. Two types of system software are the operating system and utility programs. An operating system (OS) coordinates all activities among hardware devices and contains instructions that allow you to run application software. A utility program performs specific tasks, usually related to managing a computer, its devices, or its programs. You interact with software through its user interface.

                               

Application software consists of programs that perform specific tasks for users. Popular application software includes word processing software, spreadsheet software, database software, and presentation graphics software. Application software can be:-

ü  packaged software (copyrighted software that meets the needs of a variety of users), 

ü  custom software (tailor-made software developed at a user’s request), 

ü  freeware (copyrighted software provided at no cost), 

ü  Public-domain software (software donated for public use with no copyright restrictions),

ü  Shareware (copyrighted software distributed free for a trial period).

Computer hardware components include input devices, output devices, a system unit, storage devices, and communications devices.

An input device is any hardware component that allows a user to enter data and instructions into a computer. Six commonly used input devices are the keyboard, mouse, microphone, scanner, digital camera, and PC camera.

An output device is any hardware component that can convey information to a user. Three commonly used output devices are a printer, a monitor, and speakers.

The system unit is a box-like case made from metal or plastic that protects the internal electronic components of the computer from damage. The system unit contains the central processing unit and memory. The central processing unit (CPU) is the electronic device that interprets and carries out the basic instructions that operate the computer. Memory is a temporary holding place for data and instructions.

A storage device records and retrieves data to and from a storage medium. Six common storage devices are a floppy disk drive, a Zip^® drive, a hard disk drive, a CD-ROM drive, a CD-RW drive, a DVD-ROM drive, and a DVD+RW drive.

A communications device enables computer users to communicate and exchange items such as data, instructions, and information with another computer. A modem is a communications device that enables computers to communicate usually via telephone lines or cable.