Computer Basics

 What is computer?

Computer is an electronic computing device. It takes input from its users, processes and generates desired result as an output. If, necessary input and output can be stored in computer memory for future use.

List the major functions of a computer system

1.Input

2.Process

3.Output

4.Store

What is computer program?

Set of instructions given to a computer to perform specific task is called computer program.

What is software?

Set of computer programs will make a software.

Types of Software

1.System Software

2. Application SOftware

1. System Software

These are system computer programs. These helps to helps to run/activiate all the hardware components of a machine. i.e. All hardware components starts functioning. 

System software acts as a platform to run application software.

Examples:

Operationg Systems like DOS, Widnows, UNIX, Fedora, Ubuntu, Mac OS, Android OS in mobile, etc.

Device Drivers

BIOS (basic input/output system) is the program a computer's microprocessor uses to start the computer system after it is powered on. It also manages data flow between the computer's operating system (OS) and attached devices, such as the hard disk, video adapter, keyboard, mouse and printer.

Translators

Assmbler: It is a system program that coverts the writetn program from assembly level langauge to machine level language.

Compiler: It is a system program that coverts the written program from high level langauge to machine level language AT ONCE.

Interpreter:  It is a system program that coverts the written program from high level langauge to machine level language LINE BY LINE.

Software Development Life Cycle (SDLC):

In roder to develop software by software developement companies, they pass through following steps.

1. Probleme Definition. (Given question, Client's requirement)

2. Analysis (In the mind , we prepare solution to solve the given problem)

3. Designing: It includes writing algorithm, drawing flowcharts and writing pseudocode.

Algorithm:

An algorithm is a set of instructions for solving a problem or accomplishing a task.

For an algorithm to be useful, it must satisfy five properties:

• The inputs must be specified.
• The outputs must be specified.
• Definiteness.
• Effectiveness.
• Finiteness.

Flowchart:

A flowchart is a visual representation of the sequence of steps and decisions needed to perform a process.

Peseudocode:

A mixture of natural English langauge and programming language.

4. Coding

It is the source code (computer program written by using different programmin glanaguages like C, C++, Java, HTML, C#, etc.) that the machine understands.

5. Testing

Written program will be tested for its correctness by giving deifferent set of inputs.

6. Maintenance

Give to end user(customer) to use it and it is under maintence phase. If any corrections, needed from ends users side that can be re-updated by developers.