I am so confused. Maybe it's because I'm a part-time self-taught programmer. Are we _calling_ function signatures 'APIs' just so we can speak about the topic of so much diversity in what on the face of it should all be the same implementation? Because my idea of API is the endpoint for a closed system, usually accessed over the wire.
Is this use of the term 'API' canonical or artistic license?
APIs are Application Programming Interfaces, and they have existed long before the web and web services. The article's use of APIs is correct. A really well known example of an API is the C library.
Is this use of the term 'API' canonical or artistic license?