API is another one of those TLAs (Three Letter Acronyms) that we have grown to hate and it does not stand for Apple Pie International. It actually stands for Application Program Interface and one pretty good definition is:
Application program interface (API) is a set of routines, protocols, and tools for building software applications. An API specifies how software components should interact.
Ok, so now you’ve got it right? No? The definition made it so much more clear, NOT.