When you start a new tmux session with:

tmux

If you list your tmux session with:

tmux ls

You’ll see a default name used for your sessions:

2: 1 windows (created Sat Jul 16 15:59:49 2022) (attached)

In the above the name of the tmux session is 2. Remembering these numbers can become unwheldly when you have many tmux sessions running, each with a different purpose.

The easier way to create a new session is by giving it a name of your choosing:

tmux new -s your_cool_name_here

And now when you list your tmux sessions, you can easily find the session you just created:

your_cool_name_here: 1 windows (created Sat Jul 16 16:03:46 2022) (attached)