Wednesday, 5 June 2013

WHAT IS AN OPERATING SYSTEM?


An operating system is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is a vital component of the system software in a computer system.
Application programs usually require and operating system to function.

TIME-SHARING OPERATING SYSTEMS

Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting for cost allocation of processor time, mass storage, printing and other resources.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it.

Operating systems can be found on almost any device that contains a computer, from cellular phones and video games consoles to supercomputers and web servers.

TYPES PF OPERATING SYSTEMS: 

examples of popular modern operating systems included:


  • Android
  • BSD
  • iOS
  • GNU/linux 
  • OS X
  • QNX
  • Microsoft Windows
  • Windows Phone 
  • IBM 
  • z/OS 
All these, except Window and z/OS share roots in UNIX.

iOS

 Is a mobile operating system developed and distributed by Apple.
it has been extended to support other apple such as the ipod touch.
The user interface of iOS is based on the concept of direct manipulation, using multitouch gestures. Interface control elements.