Angular's unique and innovative features are two-way data bindings, dependency injection, easy-to-test code and extending the HTML dialect by using directives. Backbone.js is a lightweight MVC framework. Full-featured MVC frameworks such as ExtJS. This resulted in many services adopting it, including Pinterest, Flixster, AirBNB and others.

https://www.airpair.com/js/javascript-framework-comparison

http://www.c-sharpcorner.com/UploadFile/f2823e/angularjs-comparison-with-backbone-knockout-part-3/

Angular.js combines the functionalities of most of the 3rd party libraries, it supports individual functionalities required to develop HTML5 Apps. While Backbone.js do their jobs individually.