Screen

To disconnect (but leave the session running)

    Hit Ctrl + A and then Ctrl + D in immediate succession. You will see the message [detached]

To reconnect to an already running session

    screen -r

To reconnect to an existing session, or create a new one if none exists

    screen -D -r

To create a new window inside of a running screen session

    Hit Ctrl + A and then C in immediate succession. You will see a new prompt.

To switch from one screen window to another

    Hit Ctrl + A and then Ctrl + A in immediate succession.

To list open screen windows

    Hit Ctrl + A and then W in immediate succession

There’s lots of other commands, but those are the ones I use the most.