alt Hacker NewsThat's pretty much the distinction. A CLI is stream-oriented, may accept user input from standard in and/or write to standard out with buffered I/O; a TUI is full-screen, interactive (responds immediately to keystrokes), and uses text characters to represent visual elements.
And that’s where my comment came in.
I see TUI as a more general term: a program based in a terminal.
In my mind it does not imply it has to be an ASCII GUI style thing and not just a stream oriented non-interactive program.