tmux:tldr:c4528
The command "tmux attach" is used to attach (or reattach) to an existing tmux session.
Tmux is a terminal multiplexer, which means it allows you to have multiple terminal sessions running within a single window or session. It is especially useful when working on remote servers or in situations where you need to keep your terminal sessions persistent even after disconnecting.
When you run "tmux attach", it will connect you to an existing tmux session. If there is only one session, it will automatically attach to it. If there are multiple sessions, it will prompt you to choose which session you want to attach to.
Once you are attached to a tmux session, you can see and interact with all the terminal sessions that were running when the session was created. You can switch between different sessions, split the window into multiple panes, detach from the session, and so on.
In summary, "tmux attach" allows you to reconnect to an existing tmux session and continue working with the terminal sessions within it.