The time sharing operating system to a allocation of the computer resources in time dependent fashion to several program simultaneously. Time sharing operating system has many user terminal that are connected to some computer simultaneously. Terminal using, different user can work on the computer at the same time. This terminal uses multi-programming with the CPU scheduling algorithm to achieve that.
In time sharing operating system, the CPU time is divided among all users on scheduled basic. Each user program is allocated very short period of CPU time. one-by-one beginning from first user program and proceeding last one, and then beginning from first on. This short period of time sharing which user gets attention of CPU is know a time slice, time slot or quantum, it is typically of the order of 10 to 100 milliseconds. The user uses CPU for the period of time slot.