Computer Operating Systems

An operating system is a set of programs that manages all computer components and
operations.A computer cannot do anything without an operating system.Operating system
must be installed on every computer.Users interact with the computer through the operating
system.when computer is turned on, the operating system properly.It manages all operations
on the computer after loading in memory.The following figure shows that an operating system
acts as interface between the user and computer hardware.
Important Operating systems
Some important operating systems are as follows:
* Microsoft windows * Linux * Unix * Mac OS * Solaris
Functions of Operating System
Operating system performs the following functions:
Booting:-
Booting is a process of starting or restarting the computer.Operating system starts the
computer to work.It checks the computer and makes it ready to work
Memory management:-
It is also an important function of operating system.The memory cannot be managed
without an operating system.Different programs and data execute in memory at one time.
If there is no operating ,the programs may mix with each other. The system will not work
properly.
Loading and Execution:-
A program is loaded in the memory before it can be executed.Operating system provides the
 facility to load programs in memory easily and then execute it.
Data Security:-
Data is an important part of computer system. The operating system protects the data stored
on the computer from illegal use modification.
Disk Management:-
Operating system manages the disk space.It manages the stored files and folders in a proper
way.Disk management is most important unit in computer operating system.
Process Management:-
CPU can perform one task at one time.If there are many tasks,operating system decides which
task should get the CPU.
Device Controlling:-
Operating system controls all devices attached to computer.The hardware devices are
controlled with the help of small software called device drivers.
Printing Controlling:-
Operating system also controls printing function.If a user issues two print commands at a time,
it dose not mix data of these files and prints separately.
Providing Interface
User interface is used to interact with computer.User Interface controls how you enter data
and instructions and how information is displayed on the screen.Operating system provides
two types of interfaces for the user.
Graphical User Interface:-
It consists of visual environment to communicate with the computer.Is uses windows,icons,
menus and other graphical objects to issue commands.
Command-line Interface:-
It provides an interface to communicate with the computer by typing commands.