Thus far, all of the options we have set had the
-g flag. This means that the option applies globally. However, there are three types of options: server options, session options, and window options.
There are also multiple flags that indicate how a given option should affect or be affected. This sounds complex, but it's rather simple.
A server option will apply to any client that connects to tmux. Under the hood, when you type and run the
tmux command the first time, tmux creates a server; then, it creates your client and connects to the server it started. This is the magic that allows you to detach your session, reattach it later, and have everything running as you left it because the tmux server keeps chugging in the background. So ...