The Teletype Model 33 was a very successful computer terminal in the late 1960s and 1970s. It has an important historical role in several innovations, including the ASCII character set and the development of Unix and BASIC.
The history of the teletypewriter – mechanical devices for digital communication – spans from early electrical communications to global news and messaging networks.
In the early 1960s, teletypewriters proved to be an ideal interface for the first time-sharing computer systems such as CTSS. People side-by-side or in different locations, each operating a terminal, could simultaneously work at the same computer, coordinate their activities, and even communicate with each other! Increasingly, the larger general-purpose computers became connected by networks too.
With the affordable Model 33 Teletype, interactive terminals became the standard UI for minicomputers such as the DEC PDP-7, PDP-8 and PDP-11, and as consoles for the first generation of personal computers including the Altair 8800.
Hard-copy (printing) terminals were superseded in the 70s by the "glass TTY" (DataPoint 3300, ADM-3A, VT-05 and many more) and increasingly smart video terminals that had nice fonts, even color and graphics. These had obvious advantages in flexibility (particularly for text editors), performance, convenience and eventually in cost. So the Teletype machinery became obsolete, but its data formats (8-bit serial data, ASCII text) and the central expectations of what a terminal could do (interactive input and output) are still baked into every modern operating system. In this sense the Teletype is "compatible". PC-compatible, Linux-compatible, Android-compatible, Internet-compatible, because it's the foundational interactive Input/Output device.