Google App Engine
Google App Engine (GAE) is commonly defined as a platform as a service (PaaS) part of Google Cloud Platform. The definition of such a service is based on the level of resources managed by the platform. Unlike infrastructure as a service (IaaS) or back end as a service (BaaS)—which primarily manage maintenance tasks such as hardware replacement—with a service like App Engine you do not need to care of things like load balancing, instance management or scaling, and so on. Think of it from a duty standpoint. When using IaaS, your responsibility begins with the operating system, whereas in PaaS, your responsibility starts with the code for your application.