SCREEN's main feature is to "multiplex" your terminal, so you can run several programs as if they were running on several windows. You always take a look at one window - but you can easily switch from one to another.

SCREEN also allows to create screendumps from windows (aka hardcopy), it keeps a backlog for each window for the text that scrolls off, and you can keep logfiles for all data that appears in the windows.

SCREEN allows you to copy&paste text from the current window (and its backlog) to a copy buffer; the contents of that buffer can be written to file or pasted into another window. (do you still need a mouse for that?)

SCREEN adds digraph input so you can enter special characters using keyboards which do not have them as a key (eg umlauts), and it keep your programs alive while you are offline, so you can log out - and when you log in again then you simply "reattach" to the SCREEN session.

You can also "lock" your session so nobody can use your open terminal.                                                                  SCREEN can also monitor the hidden windows for both activity and silence; so SCREEN cann tell you when something happens on an invisible window - or when nothing has happened for N seconds (eg after a compilation has completed).

And SCREEN allows to define who can attach to your seesion and see what you are typing.  You can even allow others to type into your window's process. (That's very useful for administrators who try to help their users using a progr
am.)                                                                            So share your terminal with others - see what they type - be coproductive!