Application Business Logic – Intro
As your application gets bigger you’ll see that you have several controllers, and every one of them controls a different part of your application. The most common usage of controllers is to communicate between the view side and the data/logic side of the application. It is a common mistake to want to put all your logic in the controller. In general, writing your logic in the controller is not recommended since the controller is better used for merging the data and the view.
The AngularJS developers thought about this, and created the AngularJS services for this task.