$ [cmd] [args] &
To lists the jobs that you are running in the background, enter the command:
To kill a job running in background, using the kill command.
The video demo how it work on Raspberry Pi. A lxtask is open to monitor the running process. And two terminal are opened to run host (on right side) and client (on bottom-left). The host program is a long-running program. The client program send request to host. To know more about it, read the post "Java exercise - Client and Server example II, ServerSocket stay in loop". The video show how to run the host program in background.