Add more information about the observers

Author: mgechev

README.md

@@ -757,9 +757,9 @@ will produce the same result as the one above. The main difference here is that
 
 ![Observer](./images/observer.png "Fig. 7")
 
-There are two basic ways of communication between the scopes in an AngularJS application. The first one is calling methods of parent scope by a child scope. This is possible since the child scope inherits prototypically by its parent, as mentioned above (see [Scope](#scope)). This allows communication in a single direction - child to parent. Some times it is necessary to call method of given child scope or notify it about a triggered event in the context of the parent scope. AngularJS provides built-in observer pattern, which allows this. Another possible use case, of the observer pattern, is when multiple scopes are interested in given event but the scope, in which context the event is triggered, is not aware of them.
+There are two basic ways of communication between the scopes in an AngularJS application. The first one is calling methods of parent scope by a child scope. This is possible since the child scope inherits prototypically by its parent, as mentioned above (see [Scope](#scope)). This allows communication in a single direction - child to parent. Some times it is necessary to call method of given child scope or notify it about a triggered event in the context of the parent scope. AngularJS provides built-in observer pattern, which allows this. Another possible use case, of the observer pattern, is when multiple scopes are interested in given event but the scope, in which context the event is triggered, is not aware of them. This allows decoupling between the different scopes, non of the scopes should be aware of the rest of the scopes.
 
-Each AngularJS scope has public methods called `$on`, `$emit` and `$broadcast`. The method `$on` accepts topic as first argument and callback as second. We can think of the callback as an observer (in JavaScript the functions are first-class):
+Each AngularJS scope has public methods called `$on`, `$emit` and `$broadcast`. The method `$on` accepts topic as first argument and callback as second. We can think of the callback as an observer - an object, which implements the `Observer` interface (in JavaScript the functions are first-class, so we can provide only implementation of the `notify` method):
 
 ```JavaScript
 function ExampleCtrl($scope) {
@@ -785,6 +785,8 @@ The scope in the example above, triggers the event `event-name` to all scopes up
 Analogical is the case when the method `$broadcast` is called. The only difference is that the event would be transmitted downwards - to all children scopes.
 Each scope can subscribe to any event with multiple callbacks (i.e. it can associate multiple observers to given event).
 
+In the JavaScript community this pattern is better known as publish/subscribe.
+
 #### Chain of Responsibilities
 
 >The chain-of-responsibility pattern is a design pattern consisting of a source of command objects and a series of processing objects. Each processing object contains logic that defines the types of command objects that it can handle; the rest are passed to the next processing object in the chain. A mechanism also exists for adding new processing objects to the end of this chain.
@@ -1016,3 +1018,4 @@ And the following partial:
 4. [Page Controller](http://msdn.microsoft.com/en-us/library/ff649595.aspx)
 5. [Patterns of Enterprise Application Architecture (P of EAA)](http://martinfowler.com/books/eaa.html)
 6. [Using Dependancy Injection to Avoid Singletons](http://googletesting.blogspot.com/2008/05/tott-using-dependancy-injection-to.html)
+7. [Why would one use the Publish/Subscribe pattern (in JS/jQuery)?](https://stackoverflow.com/questions/13512949/why-would-one-use-the-publish-subscribe-pattern-in-js-jquery)