Layar is augmented reality application on your mobile phone which shows what is around you by displaying real time digital information on top of reality though the camera of your mobile phone. Content Layers are the equivalent of web pages in normal browsers. A layer is the digital view that is added to the camera view.
The Layar API allows developers to create new layers. A layer consists of three parts: The layer definition, the list of POIs (Points of Interest) and each individual POI.