All Linux shells have job control: the ability to run programs in the background (multitasking behind the scenes) and foreground (running as the active process at your shell prompt). A job is simply the shell’s unit of work. When you run a command interactively, your current shell tracks it as a job. When the command completes, the associated job disappears. Jobs are at a higher level than Linux processes; the Linux operating system knows nothing about them. They are merely constructs of the shell. Some important vocabulary about job control is: