AngularJS module are container for the different parts of your app such as controllers, services, filters, directives, etc. AngularJS modules define application and its logical entities that helps you to divide your application. So you can keep several modules inside app. AngularJS allow you to declare a module using the angular.module() method. A module can contain one or more controllers, services, filters and directives. Similarly an app can contains several modules.
Syntax
In above example we created a module called yourApp using angular.module() method. Then we added a controller yourController to this module. This is just an alternate way of defining a controller but recommended one.
See Live Example