There are times when you want to execute an application on the command-line without interrupting the most recent process or application that is running. Whilst this is very basic, I find that n00bs may not be familiar with this trick.
On the command-line, execute a process, e.g., "ping" without the trailing "&" that keeps it running in the background. Hit Ctrl-Z to temporarily stop the process.
$ ping 10.32.1.7
^Z
[1]+ Stopped ping 10.32.1.7
^Z
[1]+ Stopped ping 10.32.1.7
Activate it but run as a background process.
$ bg
[1]+ ping 10.32.1.7 &
[1]+ ping 10.32.1.7 &
Continue doing what you are doing but the process continues to run in the background.
Transfer it back as the current process.
$ fg
ping 10.32.1.7
ping 10.32.1.7
Now, the process is back as the currently running application.