Think of environment where multiple jobs are running at the same time and you want to monitor the current status of each job. One option is to use the job activity monitor.
And another way is you can use the below system stored procedures by running it against the MSDB database.
@execution_status = 1
You can check the job execution status parameter values as below.
0 = Not idle or suspended
1 = Executing
2 = Waiting For Thread
3 = Between Retries
4 = Idle
5 = Suspended
6 = Waiting For Step To Finish
7 = Performing Completion Actions