Accessing a running program or working with others interactively

If you just run a job and then close down the terminal you ran it from, normally the job will be terminated.
It would be nice to be able to leave a long job running and be able to log out and then log back in again to see how it is progressing.
though there are some simple ways to do this, working with the screen program is the real answer.
It is a poorly named and somewhat invisible program, but which has somethat can be very useful
Serves to offer multiple command-lines instead of just one
Similar in this way to tab in a webrowser

Exercises

Type:

screen

Then:

ctrl+l, n: cycle through screen windows
ctrl+l, :hardcopy RET: create a file with a copy of all inputs and outputs of your session.
ctrl+l, d: detach screen session
type screen -r to recover a detached
type exit to get out of your screen sessions