A push notification is a message that is "pushed" from backend server or application to user interface, e.g. mobile applications and desktop applications. It is more user experience specific which is different from Push technology, which pushes the requests between components such as server to server communication. A common scenario of push notification is the client application pops up a message in front of application's user information, along with the alert sounds. The notification could also be coupled with images and hypertext link in some cases. Via interacting with the push notification it usually brings up the client applications to the front.