You can see what the user is editing (as in a google table) What kind of technology?

Question

Web development

Good afternoon.
What kind of technology does Google Sheets have when you see another user typing something?
What to read? Where to dig?

Answer 1

WebSockets) Here's where to dig

Answer 2

You can't do it with sockets alone, they use a solution similar to
https://github.com/y-js/yjs
You can google something else on "concurrent editing"