When a process is set to run "in the background" no visual cue will alert you to the process. During a background process, you can continue to work normally.

A program running in background does so unattended and in parallel to other activities going on in a computer. Daemons run in background.

A DAQ system task (such as acquiring data) that occurs without interruption while another program routine is running.

a term employed in a multiprocessing environment to refer to a process which is running off-screen, invisible to the user at the workstation

Any process that is running without accepting or controlling the input of a terminal is said to be running in the background.

Processes usually running at a lower priority and with their input disconnected from the interactive session. Any input and output are usually directed to a file or other process.

in a shell context, a process is running in the background if you can type commands. While this process is running.

The background, in the context of computer software processes, refers in general to processes that are run with a relatively low priority, require little or no input, and generate a minimum of output.