What is the purpose of these JavaScript frameworks?

Question

JavaScript

I want to master at least one of the popular serious JavaScript frameworks, but first I want to find out the purpose of each of them.
I have long heard about frameworks: AngularJS, EmberJS, KnockoutJS, Backbone.js, React.

1. Which framework to learn first?
   
2. In a few words - what is the purpose of each framework?
   
3. What server technologies are each framework best compatible with?
   
4. Which of the above frameworks are no longer promising?
   

Thanks :)

Answer 1

1. Any. Try Angular, millions of tutorials. Or React - again, a lot of information. Check out Backbone - simple and clear basic concepts.
2. The purpose of absolutely any framework is to make life easier when writing tasks that are not trivial in scope.
3. Anyone with anyone, practically. React doesn't care, he is not responsible for this, Backbone and Ember out of the box are sharpened for REST.
4. The Knockout niche is already taken by React/Angular. There is very little talk about Backbone now, but still more than about Ember.

Answer 2

Answer 3

Here are details for each blog.livecoding.tv/2016/07/06/top-10-js-frameworks