Converting screen into tmux ( terminal multiplexer )

We have beutiful program called
tmux
which allows us to see multiple terminal windows at the same time. We can covert screen in doing something similar.

To split vertically: ctrl + a then |.
To split horizontally: ctrl + a then S (uppercase 's').
To unsplit: ctrl + a then Q (uppercase 'q').
To switch from one to the other: ctrl + a then tab

We can save layouts in screenrc so that we wont have to keep doing this as well.