When working on the Linux command line, you can start a task, move it to the background, and, when you’re ready to reverse the process, bring it back to the foreground. When you run a command or script in the foreground, it occupies your time on the command line – until it’s finished. When you need to do something else while still allowing that first task to complete, you can move it to the background where it will continue processing and spend your time working on something else.
The easiest way to do this is by typing ^z (hold the Ctrl key and press “z”) after starting the process. This stops the process. Then type “bg” to move it to the background. The jobs command will show you that it is still running.
Source:: Network World – Data Center