Some would say this a bit boring, but this is one of the basic of Unix or rather Linux system, the TTY, or TeleTYpewriter. TTY one of the Unix/Linux’s subsytem, the article deliver a definitive guide for TTY, what it is, why it’s important, and it could served as an introductionary for Unix/Linux admin/developer/users.
It’s a quite long article, but it’s worth to read!