Here is a side by side comparison of screen and tmux commands and hotkeys.
Function Screen tmux
Start instance screen screen -S <name> tmux
Attach to instance screen -r <name> screen -x <name> tmux attach
List instances screen -ls screen -ls <user name>/ tmux ls
New Window ^a c ^b c
Switch Window ^a n ^a p ^b n ^b p
List Windows ^a " ^b w
Name Window ^a A ^b ,
Split Horizontal ^a S ^b "
Split Vertical ^a | ^b %
Switch Pane ^a Tab ^b o
Kill Pane ^a x ^b x
Paging ^b PgUp ^b PgDown
Scrolling Mode ^a [ ^b [