HandlebarsHelper is a library for helping you precompile Handlebars v2.0 templates for Emberjs.
If you are using a version of Handlebars less than v2.0 (version of Ember.JS less than v1.9) you should use 1.1.0 of this package.
Ember Data is a library for loading data from a persistence layer (such as a JSON API), mapping this data to a set of models within your client application, updating those models, then saving the changes back to a persistence layer.
Ember.js is built for productivity. Designed with developer ergonomics in mind, its friendly APIs help you get your job done—fast.
Don't waste time making trivial choices. Ember.js incorporates common idioms so you can focus on what makes your app special, not reinventing the wheel.