AngularJS and other web frameworks provide data binding abilities (as in WPF). Is the UI bound to JavaScript variables on the frontend (web browser) or is it bound to the data in the server (via AJAX and such)?

I assumed that with all the MVC frameworks for the web, the model is the data on the server, the view is the web page on the client, and the controller is either on the server or on the client (browser). Did I get that wrong?

I’m sorry if its a stupid question. I am a C#/C++ developer but with little experience in web development.