tty
also: teletype, terminal, pts (pseudo-terminal slave), pty (pseudo-terminal)
A terminal interface that allows users to interact with the system through text input and output. Originally referred to physical typewriter-like devices, now commonly means virtual terminal emulators or terminal sessions.
TTY stands for 'teletype' and represents a character device that handles text-based communication between a user and the operating system. In modern Linux, this includes physical serial consoles, virtual terminal emulators (like those in your desktop environment), and pseudo-terminal pairs used by SSH sessions and terminal multiplexers.
Each TTY has a device file, typically located in /dev/ such as /dev/tty1 for virtual consoles or /dev/pts/0 for pseudo-terminals. You can check which TTY you're using with the tty command, and manage terminal settings with stty.
TTYs handle important functions like line editing, signal handling (Ctrl+C sends SIGINT), and job control. The relationship between a process and its controlling TTY determines how keyboard interrupts and background/foreground job management work.