A common question asked by newcomers to the world of Azure Functions, is what’s the difference between an Azure functions app vs a function? Are they the same thing?
In short, there is a difference. You can think of the functions app as if it refers to a workspace that contains one or more functions. It’s essentially a wrapper (or in .NET terms, project), holding all your Azure functions in one place and allowing for easy deployment and management of them as one.
On the other hand, a function refers to a single, isolated piece of functionality. Typically in .NET this results in a class that performs one discrete piece of behaviour.
There are a number of ramifications for function apps that don’t apply to individual functions. For instance, it’s at the function app level that the pricing plan, runtime version and more are set in Azure. Microsoft refers to this as providing the execution context for your functions.
So keep in mind that when you first create a function resource in the Azure Portal, you’re creating a functions app. Once you navigate inside that resource, you can then start to add individual functions.