Operating system manages main memory, processor, device and file system manipulation. It also responsible for protection and security of the system, control over system performance, job accounting, error detection aids, and coordination between other software and users. Operating system also supports multiple execution mode.
Goal of Operating System:
An Operating System has two goals:
(i) Efficient use of a Computer System
(ii) User convenience
An Operating System can not provide both because user convenience often conflicts with efficient use of a computer system. Efficient use is important when a computer is shared by several users while user convenience is important in personal computers.
User convenience has higher priority than efficient use of a Computer System in Windows Operating System while efficient use of a Computer System has higher priority than user convenience in Unix Operating System.