Allows for web apps and static assets (e.g., Android APK,, screenshots etc.) to be served for your app.
Storage
Allows storing of files (e.g.. photos) using Google's CDN making it reliable and scalable.
Realtime Data
Allows application data to be stored AND synched in real-time with all connected clients (including both mobile app and embedded sensing hardware).
Authentication
Allows users to create accounts and login/logout, user can then control access to various features
Messaging/Notifications
Notifications are built on Messaging. The latter is simply a way to send data messages to all connected clients - with Notifications you can automate the sending of these messages in response to the occurrence of specific events or sequences.