When you type a command on the Linux command-line, it runs in the foreground until it completes. That's fine for commands that run quickly, but if a job needs a lot of time to run, you probably want to type other things while it's running.
- put an ampersand (&) at the end of the command line to run the job in the background, e.g.
cpu123% ./my-long-job &- now the prompt stays available to run more commands
- see what jobs you have running in the background using the jobs command, e.g.
cpu123% jobs
[1] + Running ./my-long-job
- bring the first job from the background to the foreground in case you want to type at it:
cpu123% fg %1
- put the first job in the background again:
cpu123% bg %1
- terminate the first background job:
cpu123% kill %1