Let's first start with service models. When designing a bigger system, you need to decide how much of the infrastructure you will manage versus how much you can build upon existing building blocks. Sometimes, you might want to leverage existing software without the need to manually deploy an app or back up data, for example, by using Google Drive through its API as storage for your app. Other times, you can rely on an existing cloud platform such as Google's App Engine to deploy your solution without the need to worry about providing a language runtime or databases. If you can decide to deploy everything in your own way, you can either leverage an infrastructure from a cloud provider or use your company's one.
Let's discuss the different models and where each can be useful.
