It seems like Microsoft is constantly adding new services and features to Windows Azure and one of the latest services Azure provides is Azure Functions.
Azure Functions are born from the notion of Functions as a Service (FaaS) and builds on the serverless architecture paradigm that has come about recently as a new way to think about building tradition web solutions. It’s the idea of offloading work to the cloud but instead of using traditional PaaS offerings such as the Azure App Service where you still have to build your web services with WebAPI or WCF you build your functions inside the Azure Functions service and have it automatically create the HTTP endpoints, authentication and all the other management and setting up that goes around deploying web services.
You can find out more about what features and scenarios Azure Functions support by visiting http://functions.azure.com.
You might also want to read through this great article by Mike Roberts on serverless architectures.
The video below walks through creating a simple application first using a WebAPI based service and then replacing it with an Azure Function.