There are process ID numbers, and job numbers. How are they different?

-Process numbers always start at 100, while job numbers start at 1. This is because users are more likely to type job numbers and they wanted them to be shorter.

-Both are actually the same, and a job's number exactly matches the process ID number of that job.

-Job numbers are never re-used between reboots, while process ID numbers can be re-used once a program terminates.

-Process ID numbers must be unique on a system. Job number are specific to the user. So there can only be one process ID number of 57 on a system, but each user could have a job number of 2.