gnome

Back in the days, terminals were physical devices connected to a serial port each. These show up in UNIX as 'device files' in /dev.

You are running Linux, by the looks of your output, and thus there are two different types of 'virtual' terminal. The first set are those connected via your display. Linux creates a bunch of them, and you can toggle between them using Ctrl+Alt+Fn . These are tty0, tty1, etc.

Then there is the concept of a pseudo terminal. One is required for each ssh session that you use to connect to your system, and one for each (Gnome) X terminal session. These are the 'pts/n' names. Search for 'pseudo terminal' to learn more.

Thus the above output tells me that: your graphical session is tied to the 2nd virtual terminal ( Ctrl+Alt+F2 ). You have two gnome terminals, pts/0 and pts/1.

Try opening a new VT using Ctrl+Alt+F1 and log in there, and repeat on terminals 3 and 4. Each time you do this ps -ef will show the processes running with that terminal.

Background processes do not have a terminal attached, and will show ? in the TTY column.