Send to background
Syntax bg [jobspec ...]
Resume each suspended job jobspec in the background, as if it had been started with &.
bg takes a “jobspec” available from jobs, not a PID.
If jobspec is not present, the shell's notion of the current job is used.
bg jobspec returns 0 unless run when job control is disabled or, when run with job control enabled, any specified jobspec was not found or was started without job control.
This is a BASH shell builtin, to display your local syntax from the bash prompt type: help bg
Examples
Put the job with job id 0 in the background:
$ bg %0
To start a new process in the background you can do:
$ long_running_command &
“Keep your eyes on the stars, and your feet on the ground” - Theodore Roosevelt
Related macOS commands:
fg - Send job to foreground.
wait - Wait for a process to complete.