Introduction to Operating Systems

An operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs.

An OS can be defined as an interface between user and hardware or an environment in which a user can execute programs in convenient and efficient manner.
Structure of a Computer System
  • System programs: Shells, editors, compilers, etc.,
  • Operating system: A special program which acts as an interface between user and hardware, and
  • Hardware: CPU, disks, memory, etc.





      Did you ever notice that when you blow    
      in a dog’s face he gets mad at you?    
      But when you take him in a car,    
      he sticks his head out the window.