Mat Velloso explains how to create applications and services in Azure that an authenticate again Azure AD. How do you access data "on behalf of" a user in a secure way. Let's make apps that access a users' calendar or mailbox in the cloud! We'll do it for real, using C# and Visual Studio, but talking JSON and REST over HTTPS. Be sure to watch this short companion video on REST in a cloud context: HATEOAS, REST, and Hypermedia Primer with Mat Velloso