What is the difference between an API App and a Web App?

Question

I've been reading a few tutorials now on deploying Web Apps and API Apps to Azure. However, I am still a little unsure as to why you would use one over another.

I can create a new .NET solution with API controllers and deploy this as a Web App, so why would I specifically require an API App? Are these optimized specifically for ASP.NET Web API, where as Web Apps are for delivering HTML?

Answer 1

The only difference between the three app types (API, web, mobile) is the name and icon used for them in the Azure portal. So it no longer matters which app service type you choose to deploy to (unless you care what the icon looks like). Function apps are now the exception. Creating a function app changes the user interface in the portal. The underlying web app, however, is no different. Setting an app setting named FUNCTIONS_EXTENSION_VERSION = ~1 turns any web app into a function app (minus the user interface in the portal).