Something about Operating Systems...

                                                                            

           An operating system (OS) is a set of software that manages computer hardware. Definition of an OS is the set of software that controls the overall operation of a computer system, typically by performing such tasks as memory allocation, job scheduling and input & output devices.Without an operating system, a computer is useless.
          
         Operating System is a vital component of the system software in a computer system. The operating system act as an intermediary between program and computer hardware. The first computers didn't have an operating system.


Operating systems can be classified as follows:

• Multi-user 

           Allows 2 or more(can be thousands) users to run programs at the same time. 

• Multiprocessing

           Supports running a program  on more than one CPU.

• Multitasking 

            Allows more than one program to run concurrently.

• Multithreading

          Allows different parts of a single program to run concurrently.

• Real time

           Responds to input instantly.

  Popular operating systems 

1. Linux (Ubuntu, RedHat, Fedora, Dabian, DSL... and many more)
2. Windows OS ( XP, Vista, Windows 7 ...etc)
3. Mac OS
4. Unix
5. Sun Solaris OS

OS platform Statics in 2012

                        

                  Windows                  83.6%

                  Mac OS                      9.0% 

                  Linux                          4.9%

                  Mobile                        1.6%

User interfaces of popular operating systems

Ubuntu(Linux)

              

                   Windows

                                                                     

 Android(Linux; for mobiles)