Most likely you entered the server just via SSH connection. But if suddenly you entered the server through the console of your personal account, since you have a server in which the SSH program has not yet been installed, then follow the steps below:
It can be very convenient to divide the terminal screen into several separate windows that will work even if you close the SSH connection. This may be necessary if you need to run the execution of some program without a service file / docker.
sudo apt install tmux
tmux
Now briefly about how to manage tmux:
split horizontally: press Ctrl+bremove your fingers from the keyboard, thenShift+”
Split vertically: press Ctrl+brelease and thenShift+%
transition between panels: press Ctrl+b and arrow in the desired direction.
close one of the panels:Ctrl+b and x
If the server is closed, then the windows created in tmux do not disappear, and all active programs continue to work in them. That's why: