Student provides and important data structure: A job pool.
A job pool on discovers the OS to select which job run next, to increase CPU utilization.
1. When a job came in directly on cards on even or magnatic tape, It is not possible to run a job in a different order they must be runes sequently or FCFS (First Come First Serve).
2. When jobs are in direct access device. Such as it is disc job scheduling became possiable.
The most important aspect of job scheduling is a ability to multi program. Multi program mean increases CPU utilization by organizing jobs such that the CPU always has one to execute.
The idea is follows the operating system keeps several jobs in a memory at a time. The set of jobs is a subset of the job kept in the Job pool.