The shell can run more than one job at a time. While one is running in the foreground, one or more can be running in the background.

After you enter a command, you see the output from the command displayed on your screen. You cannot enter any other commands until the shell prompt ($ or >) appears. This command has run as a foreground job. Commands that take a few seconds to complete are convenient to run in the foreground.

You may prefer to run as background jobs those shell commands that take longer to run, because they prevent you from running any other commands while they are running in the foreground. The shell does not wait for the completion of a background command before returning a prompt to you. Instead, while the command runs in the background, you can continue entering other commands on the command line.

In TSO/E, a background job is one that is typically entered at a workstation by a SUBMIT command. Like a TSO/E background job or a batch job, a z/OS UNIX background job runs without user interaction.