Ctrl+Z and fg

Ctrl+Z: Some people use Ctrl+Z to stop a command that is running interactively on the
console (in the foreground). Although it does stop the command, it does not terminate
it. A command that is stopped with Ctrl+Z is merely paused, so that you can easily start
it in the background using the bg command or in the foreground again with the fg
command. To start the command again, you need to refer to the job number that the
program is using. You can see a list of these job numbers using the jobs command.