TMux is a "terminal multiplexer: it enables a number of terminals (or windows), each running a separate program, to be created, accessed, and controlled from a single screen. TMux may be detached from a screen and continue running in the background, then later reattached."

tmux is an ISC-licensed alternative to GNU Screen. Although similar, there are many differences between the programs, as noted on the tmux FAQ page.

Install the tmux package.

Ubuntu:

sudo apt install tmux

Fedora:

sudo dnf install tmux

macOS:

brew install tmux

By default, tmux looks for user-specific configuration at $XDG_CONFIG_HOME/tmux/tmux.conf followed by $HOME/.config/tmux/tmux.conf, as of 3.2. A global configuration file may be provided at /etc/tmux.conf though by default Arch does not ship such a file.

• Arch Linux: TMux manual page