Google App Engine
Google App Engine is a platform designed for building scalable web applications and mobile backends. It includes built-in services designed to scale your application automatically, allow for easy authentication, and store data in familiar NoSQL datastores. Google even manages your app’s availability, so there are no servers to deploy or maintain.
Google Compute Engine
Google Compute Engine is Google’s infrastructure virtualization platform. GCE delivers virtual machines across Google’s global infrastructure, enabling scaling from a single instance, to global, load-balanced computing. These virtual machines boot quickly, are available with multiple OS configurations, and can even be optimized for your specific needs.
Google Cloud Datastore
Google Cloud Datastore is a highly-scalable NoSQL database which automatically handles sharding and replication of your data. This provides highly available and durable databases which can scale automatically with your applications load. Additionally, it’s well integrated across the rest of Google’s Cloud Platform, being accessible from both Google App Engine and Google Compute Engine, as well as other parts of the platform.