tmux is a terminal multiplexer, which mean allows users to be created and accessed multiple virtual terminals from a single screen. This is also an alternative to the screen command. tmux can be detached from the screen to run in the background and re-attach again later, so you can read more about the description of tmux here https://man7.org/linux/man-pages/man1/tmux.1.html#DESCRIPTION
Read More >> https://linux-id.net/tmux-command-cheatsheet/