> A pts is pseudo-terminal - in this case, it's the virtual terminal that
> the window manager has created for your shell to run in, hence why it's
> returned by a command in that shell.
> A tty is physical terminal - in this case, tty7 is 'terminal' X11 is
> running on, and that you used to log in to the computer, hence why it's
> returned by the 'who' command.
I have only a vague grasp of these concepts. So login was on tty7. Which
presumably launched Ubuntu. From where I launched fish in pts4. Can you
refer me to an easy-reading reference on all those goings-on?