Schedulers are specialised computer programs that manage process scheduling in a variety of WAYS. Their primary responsibility is to choose which jobs to submit into the system and which processes to run.

Following are the three types of schedules:

• Long Term Scheduler: It is also known as a job scheduler. A long-term scheduler determines which programs are accepted for processing into the system. It chooses processes from the ready queue and loads them into MEMORY so they can be executed. For CPU scheduling, the process loads into memory. The job scheduler's main goal is to deliver a balanced mix of jobs, such as I/O bound and CPU bound WORKLOADS. It also regulates how much multiprogramming is done. If the degree of multiprogramming remains constant, the average rate of process creation must be equal to the average rate of process departure from the system.
• Medium Term Scheduler: Medium Term Schedulers are used for swapping processes in the main memory. It clears the memory occupied by the processes. The degree of multiprogramming is reduced as a result. The SWAPPED out-processes are handled by the medium-term scheduler.
• Short Term Scheduler: It's also REFERRED to as a CPU scheduler. Its primary goal is to improve system performance in accordance with the set of criteria established. It is the transition from the process's ready to running stage. The CPU scheduler chooses a process from among those that are ready to run and allocates CPU to that process. Short-term schedulers usually referred to as dispatchers, decide which process to run next.