Merge pull request #3929 from shaedrich/backbonejs

Add related and extend description of topic "Backbone.js"

Author: underwoo16

topics/backbonejs/index.md

@@ -8,5 +8,12 @@ short_description: Backbone.js is a JavaScript library for building modern web a
 topic: backbonejs
 url: https://backbonejs.org/
 wikipedia_url: https://en.wikipedia.org/wiki/Backbone.js
+related: javascript, mvc, underscore, routing, jquery
 ---
-Backbone supplies structure to JavaScript-heavy applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing application over a RESTful JSON interface.
+**Backbone.js** supplies structure to JavaScript-heavy applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing application over a RESTful JSON interface. Backbone.js was originally extracted from the Rails application [DocumentCloud](http://www.documentcloud.org/). Philosophically, Backbone is an attempt to discover the minimal set of data-structuring (models and collections) and user interface (views and URLs) primitives that are generally useful when building web applications with JavaScript. Backbone is a library, not a framework. Synchronous events are used as the fundamental building block over constantly polling data. The main pars of Backbone are:
+* Events
+* Models – Wraps a row of data in business logic. 
+* Collections – A group of models on the client-side, with sorting/filtering/aggregation logic. 
+* Router (+ History)
+* Views (+ Client-side Templates) – A logical, re-usable piece of UI. Often, but not always, associated with a model.
+* Sync – Synchronization between frontend and REST API backend