Let's say that you are running a command on a linux shell and it's taking a long time. Further, you need to disconnect your session to get on the bus or your session gets disconnected because your net connection is flakey.
Screen to the rescue
Imagine if you could just disconnect from your shell session and then reconnect. Well, you can :)
Screen Cheat Sheet
|What it does
|make a new screen
|"next screen down the line"
|"previous screen down the line"
|kills current screen until last one then you're out
|leave, but leave them running and re-attachable
|screen -r 31619.something.else
|re-attaches to that session
So - that quick guide should provide the commands you need in the order you need them. And then you'll be more productive and then you'll be happier because you'll be doing it efficiently :)