Google Cloud Messaging (GCM)
Google Cloud Messaging for Android (GCM) is a service that helps developers send data from servers to their Android applications on Android devices. The service provides a simple, lightweight mechanism that servers can use to tell mobile applications to contact the server directly, to fetch updated application or user data. The GCM service handles all aspects of queuing of messages and delivery to the target Android application running on the target device.
The Google Cloud Messaging (GCM) is to use the Google Cloud Messaging framework in your Android application. You will get configuration and setting up GCM in Android.
DCM consists of two part –
1. A web server containing a page where you can send messages
2. An Android application that receives and displays such messages.
Details information about API reference documentation are available here –