[rsp1984]

Thank you. I think it's a bit misleading then to call it a "terminal emulator". It's not really emulating one of those old boxes, is it? It's providing a text interface to a computer's functions. That's great but it's not emulating anything.

[debugnik]

It emulates them in the sense that they implement a virtual display and keyboard for the same wire protocols those old boxes used. Those protocols are mostly plain text, but also escape sequences for cursors, colors, layout, etc. Check out the VT100 sequences for example.