AngularJS is making it really easy to build feature-rich websites. Especially things like 2-way-databinding and that you don’t have to mess around with things like DOM-manipulation making it very easy to build websites. This framework solves a bunch of problems for you.
If you’ve never heard of it, first go to the official website and have a look around.
After that, watch the excellent AngularJS intro by Dan Wahlin who goes through all the basic fundamentals in about 60 minutes. It’s the best introduction I’ve seen so far for AngularJS.