Use of NSNotificationCenter object to post and observe notification broadcasted within a program.

NSNotificationCenter is a class which helps to broadcast information within a program. Once the objects is register as a observer of a notification with a particular "notification_name' then every time the notification is posted with "notification_name" by any object, the active observer of that notification is notified. This simple post will show you how you can make use of NSNotificationCenter in your application.