Introduction

Operating System

Operating System is the software system, which manages the computer to coordinate all the works.

Types of OS

1.                  Single user single tasking O/S à        Ms-DOS

2.                  Single User Multi tasking O/S            à        windows

3.                  Multi user Multi tasking O/S  à        UNIX

4.                  Networking O/S                                  à        Windows -NT

Language

Language is a tool for communications. We can interact (work) with system          by using a System language.

There are three types of languages

1.                  High Level language:

Commands will be similar to English language. Commands like CLEAR, GET and PRINT will do the work of clearing, getting input and printing.

So it is very easy to develop a program using high-level language. But each & every command should be        converted into machine-readable format (0s and 1s), and then it will get executed.

So program development is easy, but execution of program is slow.

Ex:       BASIC ,FORTRAN

2.                  Low Level language:

Low-level language deals directly with the memory of computer. So we have to refer abbreviations, address of memory and hardware and etc. So program development is tough, but execution of program is fast.

Ex:       Assembly languages

3.                  Middle Level language:

Takes features from high and low level languages. Easy to develop, fast in execution, middle level languages became programmer's languages.

Ex:       c, c++

Converter

The converter means nothing but, to convert the source code into machine understandable code. The converter is classified into following types.

1.      Assembler:

The assembler is used to convert the assembly language source code into machine understandable code.

2.      Compiler:

The compiler is used to check any syntax errors are available in our source code or not. Whenever it is checking at that time it will check whole program at a time. After compiled we should correct  all errors. After compiling a file is created with extension OBJ.

3.      Interpreter:

The interpreter is also used to check if any error is available in our source code or . The  checking is done statement by statement. While interpreting the source code is linked with the built-in statements (Function). Before interpreting you should compile your program. After interpreted only we can able to see the output (Re-action of our program).