Launches Tmux terminal session with 1 window.
You enter "tmux" command any number of times, but everytime you run the command a new session will be created in addition to the current one.
Sessions are numbered starting from 0.
The sessions shall be active and running even if you close the terminal window - in fact, this why you want tmux.
To connect to an existing session, use the command "tmux attach -t 0"
Zero is the session number in the above example.
To split the screen horizontally use Ctrl B " (ie., contrl+B and then double quote)
To split tmux screen vertically use the command Ctrl B %
You can close the split window, simply use "exit" command.
To switch between the split screens, use Ctrl B followed by arrow keys.