A terminal is a tty (text input/output environment). A Linux console terminal is one of the system consoles provided in the Linux kernel. The Linux console terminal is usually used to provide text user interface applications and important kernel messages. In many Linux distributions, the default user interface is the real terminal, though virtual consoles are also provided. The console terminal has its own terminal screen, unlike the virtual console terminal, which needs to share the monitor screen. It's a program called a terminal emulator. This is a program that opens a window and lets you interact with the shell. A terminal is a particular kind of device file which implements a number of additional commands (ioctls) beyond read and write. A terminal window, also referred to as a terminal emulator, is a text-only window in a graphical user interface (GUI) that emulates a console.