As a tech oriented site we're nearly all accustomed to unix/unix-inspired general purpose CLIs. However that's not all that exists. There exist more specialized systems, such as those designed to be used over teletype machines, that present the user with a pre-defined menu prompt at each step in the interaction. However unlike with voice-oriented systems, the user can sit there and read the entire list of options for as long as they'd like. You connect, and a menu prints out. You press a key to make a selection and a new menu prints out, or the system prompts you to enter a different sort of data.

Think back to the earliest programming courses people take:

    What's your first name: Jack
    What's your last name: Ch
    Hello Jack Ch!