A task can usually be started and run as a background task by putting a '&' at the end of the command line.
If a task was started and is running in the foreground, it is still possible to move it to the background without cancelling it. To move a task from the foreground to the background perform the following steps:
The job is now running in the background.
Useful commands to see which jobs are still running is the 'jobs' or the 'ps ua' commands. If the 'jobs' command is used, a background jobs can be brought to the foreground with the command fg n where n is the job (not the PID) number.