If you use SSH to work on a remote Linux server, tmux is one of the first tools worth learning.
The problem it solves is simple: if your SSH connection drops, anything running in that terminal usually stops with it. That is a bad fit for long-running work like Codex, editors, logs, build processes, servers, or monitoring tools.
tmux gives you a persistent terminal session on the remote machine. You can disconnect from SSH, come back later, and continue exactly where you left off.
