I'm trying to understand what an API is. Consider the special case of PyGame Zero, which is an API.
Wikipedia says that an api is
a way for two or more computer programs to communicate with each other.
What are the two (or more) programmes that PGZ interfaces between? Is there an easy way to find this out for an API in general?
Well, just let's say the Wikipedia article describes an "older" point of view to the term (the part with two connected computers).
The still relevant part is that API is short for application programming interface.
Nowadays and more colloquial the term API is more tied to the "interface" part.
Each library, each framework and even the networked services (still) have an API.
It just means you have methods and classes that let you programm your application. And as the article states most commonly the API let you do that in a black box manner without needing deeper insights how the API is doing their part.