Schedulers are specialized computer programs that control the scheduling of processes in various ways. Their main task is to decide which jobs to enter into the system and which processes to conduct.

The three types of schedulers are as follows:

• Long Term Scheduler: A job scheduler is another name for a long term scheduler. Which applications are admitted for processing into the system is determined by a long term scheduler. It selects processes from the ready queue and loads them into memory before executing them. The process is loaded into memory for CPU scheduling. The basic purpose of the job scheduler is to deliver a well-balanced mix of jobs, such as Input and Output and CPU bound workloads. It also controls the AMOUNT of MULTIPROGRAMMING done. The AVERAGE rate of process formation must be equal to the average rate of process departure from the system if the degree of multiprogramming remains constant.
• Medium Term Scheduler: This TYPE of scheduler is used to swap programmes in the main memory. It frees up the RAM that the processes have used up. As a result, the degree of multiprogramming is minimized. The medium-term scheduler is in charge of the swapped out processes.
• Short Term Scheduler: A CPU scheduler is another name for a short term scheduler. Its main purpose is to increase system performance in ACCORDANCE with the stated set of criteria. It is the shift from the ready to the running stage of a process. The CPU scheduler selects a process from among those that are ready to run and gives it CPU time. Short term schedulers, often known as dispatchers, choose the next process to run.