How to rename a session in Tmux

Tmux is a Linux package that allows you to multitask between terminal windows. Terminal Multiplexing is an acronym that is based on the notion of sessions. It may be isolated from a screen and run in the background before reattaching. Tmux is a terminal multiplexer that may be substituted for the GNU screen. You can create a Tmux session and then open many windows within it. Each window inhabits the entire screen and is separated into rectangular panes.

Source: FOSS Linux