Hi,
I do not have exact details on difference between these technologies but you can refer http://scn.sap.com/community/developer-center/front-end/blog/2013/03/19/how-to-build-testable-sapui5-applications where it is mentioned that,
new client-side Web frameworks have emerged, for example Backbone.js, AngularJS, and Ember.js. SAPUI5 belongs to the same group of frameworks with the additional advantage that it also serves as a widget library.
Regards,
Chandra