As a advanced screen user, then total newbie tmux user, one could be annoyed about the status bar at the bottom if starting up tmux for the first time. This is the default setting in tmux.
This particular explained setting is useful if tmux is running only one instance of only one application and there is no plan to add more to tmux, much like dropping the multiplexer functionality from tmux and running it like screen in the default state.
Set the status bar at the bottom of tmux session to off, make this thing disappear:
tmux set status off
Set the status bar to on, make this thingy visible:
tmux set status on
To show the current status of use following command
tmux show status