Types of Schedulers

1. Long-Term Scheduler (Job Scheduler)

• Decides which processes to admit to the system.
• Determines the degree of multiprogramming.
• Responsible for allocating resources.

2. Short-Term Scheduler (CPU Scheduler)

• Decides which process to execute next.
• Allocates CPU time to processes.
• Switches between processes quickly.

3. Medium-Term Scheduler (Swapping Scheduler)

• Decides which processes to swap in or out of memory.
• Manages memory allocation.
• Helps to improve system performance.

Comparison

Type	Function	Time Scale
Long-Term Scheduler	Process admission	Long-term (minutes, hours)
Short-Term Scheduler	CPU allocation	Short-term (milliseconds)
Medium-Term Scheduler	Memory management	Medium-term (seconds, minutes)