In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an early form of human–computer interaction, before the advent of bitmapped displays and modern conventional graphical user interfaces (GUIs).
Just of note, TUI stands for terminal user interface, not text!
edit: I have been corrected, both are acceptable! Who knew?
Both definitions seem to be present:
https://en.wikipedia.org/wiki/Text-based_user_interface
Huh, I didn’t know that. Pretty interesting! I wonder how many acronyms have multiple different long forms…