CPU scheduling is the basis of –

The objective of multiprogramming is to have some process running at all times to maximize CPU utilization.

• The Mechanism: In a multiprogramming system, several processes are kept in memory at once. When one process has to wait (for example, for an I/O operation), the operating system takes the CPU away from that process and gives it to another.

• The Role of Scheduling: CPU scheduling is the specialized software mechanism that decides which of the ready processes in memory gets the CPU next. Without scheduling, the system would essentially be a "single-tasking" environment where the CPU sits idle whenever a process waits for I/O.