BASIC CONCEPTS OF COMPUTER

DEFINITION OF COMPUTER
Computer is an:

• electronic device
• accepts and stores input
• manipulates it
• outputs result
• under the direction of stored programs and instructions

DATA AND INFORMATION

Data is raw facts and figures.

When data is processed to make it meaningful it becomes Information.

Example:

Data: India, 200, 4, cricket, wicket

Information: India beats Pakistan in cricket match by 50 runs.

WHAT IS HARDWARE

Hardware refers to physical and tangible (touchable) components of computer.

Example: CPU, Keyboard, Monitor, Mouse, Printer

WHAT IS SOFTWARE

Software is a set of programs which make the hardware of the computer work. Software is abstract in nature that is it cannot be felt and touched.

Computer is a dumb machine without the software.

A computer needs to be instructed to perform and give output.

The set of these instructions is known as a Program.

Example: MS Paint, Corel Draw, Notepad, etc.

TYPES OF SOFTWARE

• APPLICATION SOFTWARE

set of programs necessary to carry out operations for a specified application.

1. PACKAGES: they are general application software. Most common categories are:
   a) Word Processing Software: e.g. MS Word, Wordstar, etc.
   b) Spreadsheets: e.g. MS Excel, Lotus 123, etc.
   c) Database Management Systems (DBMS): e.g. Foxpro, MS Access, Oracle, etc. d) Desktop Publishing Packages (DTP): e.g. CorelDraw, Powerpoint, etc.

2. UTILITIES:are those application programs that assist the computer by perfrorming housekeeping functions like backing up disk or scanning/clearing viruses. Some of the utilities are: Text editor, backup utility, Compression utility, Antivirus software.

3. CUSTOMISED SOFTWARE: tailor made software according to users needs.

SYSTEM SOFTWARE

System software controls the internal functioning of the computer.

1. OPERATING SYSTEM: software which acts as an interface between the user and the hardware.
   
   Note: refer to the post about Generations of computer languages for a better understanding of the text given below.
   

2. LANGUAGE PROCESSOR: software which converts High Level Language (HLL) into Machine language. There are three types of language processers.

a) Assembler: converts program written in Assembly language into machine language.

b) Compiler:

1) converts program written in HLL to machine language in one go.

2) after the compilation compiler is removed from the memory.

c) Interpreter:
1) converts the program written in HLL into machine language line by line.

2) It is resident in the memory till the entire conversion takes place. Therefore, unnecessary usage of memory.