What is a TTY on Linux? (and How to Use the tty Command)
What does the tty command do? It prints the name of the terminal you’re using. TTY stands for “teletypewriter.” What’s the story behind the name of the command? That takes a bit more explaining.
— Read on www.howtogeek.com/428174/what-is-a-tty-on-linux-and-how-to-use-the-tty-command/