how to create push notification in Android using GCM or either C2DM i have tried and check some sites and didn\'t get exact answer.i need to know how it works.Can any one pr
Its Depend on your requirement what you have to do.
here is sample of C2DM: in this sample android device is registered wtih server after that server send massage to all device. so there is one way communication(server to Android device)

So all things are done at server side. just download this tutorial. Both Server side(PHP) and Android code are available.
you got application key from Google services which you have to put at server side.
SENDER_ID – Google project id which you have to send when you want to register your device with server.