Data and Information

Data is a collection of raw facts and figures , It comprises symbols , numbers , words or images. The data may be the result of any experiment or observations of a variable.

The processed data or manipulated data is called. information

The process on data means to add some knowledge or manners in the raw facts or in the content of computing to perform some arithmetic or logical operation on it .

Data compression

Data compression is a process of encoding applying some specific encoding scheme. Data compression is also used is data transmission.

Need of compression

compression is useful because it reduces the consumption of expensive resources like hard disk space or transmission band width.

• To reduce the storage space
• To increase the capacity of communication channel
• Information security

Large amount of data requires more memory for storage. Data compression is helpful if you want to store data and there is less space on hard-disk  

Operating System

Operating system :-An operating system is the software that uses the raw capabilities of hardware and build a platform for execution of program. the operating system manages hardware resources ,provides facilities for accessing those resources and creates higher level ab station like file directories and process.

Typical computer contains 5 major components:

1.  Hardware
2. Operating system
3. System programs
4. Application programs
5. User

Structure of operating system

Process Management:-A process is an existing program . Associated with process are its code , its data , a set of resources allocated to it and one or more “flows” of execution through its code.

Memory management:-At a minimum ,memory must be shared by an application program and operating system .

File system management:-Computer process information that must be transmitted , processed and stored at a proper location in programming drive .

Device management:- A computer communicates information with its input and output devices . Processes access those devices with the operating system supervisor .call provided for that purpose

Types Of Systems Software

Software are of two types. They are

• Application software
• System software

Application software consists of the programs that perform tasks particular to the machine,s utilization.

System software act as an interface between the hard ware of computer and the application software that users need to run on the computer.

Main functions of operating system are as follows:-

• It recognize input from the key board , send output to the screen ,and keeps the track of files and directories on the disk and also control printer , CD-ROM,etc.
• It checks whether different program and user running at same time do not interfere with each other
• It gives the software platform on which the other application software and program can run.

Compiler is the system software that accepts program written in higher languages and translate them into machine languages.

Preprocessor is a program that processes its input data to produce output that is used as input to other program such as compiler.