Job Management

• Job: A job is an independent task submitted by a user to the operating system for completion, representing a collection of work required from the computer.
• Job Step: To obtain results, every job must undergo several relatively independent yet interrelated processing steps; each such step is referred to as a job step.

Differences Between Jobs and Processes

• A single job may consist of multiple job steps, corresponding simultaneously to multiple processes (and comprising at least one process); however, the converse does not hold true.
• The concept of "job" is primarily applied in batch processing systems; conversely, the concept of "process" is utilized in virtually all multiprogramming systems.
• The primary function of job scheduling is to verify whether the system can meet a job's resource requirements and then schedule jobs from the external memory backup queue into main memory according to specific algorithms, creating processes for them and inserting them into the process ready queue to await process scheduling. Process scheduling, on the other hand, allocates CPU time to one of the processes in the ready queue based on certain algorithms so that it can execute.