Different technically solution, nothing else.
@Jagster was faster. Also, my explanation may be a bit vague, but I’m sure there are experts here that will be able to explain it better!
This deserves some elaboration.
For a start:
- workload: relieves the server from a lot of work so helps the website scale better (hey, get the users machine to share some of the work, why not?!)
- UI: improves the dynamic nature of the UI so the user experience is better (e.g. click a button to update only a portion of the screen - no big whole browser repaints).
I’m sure there are plenty of other advantages but those are the basic ones.
From client’s side and for an end user it is pure JS, or looks that way, right?