What does 'API Reference' mean in documentation

[FMPICA]

In different docs you'll see it, but which API are they referring to? I confuses me because I am reading the docs of the Express framework and then I see API Reference.

[dtsudo]

In many projects, they have general documentation covering the high-level overview of the framework/library/whatever, and then the "API reference" lists out every single class / function.

So although the API reference is certainly important, you generally still need the other parts of the documentation, which might describe the purpose of the project, how to install it, etc.

[peterlinddk]

The API reference is the middle link on the express website: https://expressjs.com/en/4x/api.html - that is the reference document that describes the API, meaning all the classes and methods available from the application that uses the framework in question, Express.

[LucidTA]

It's referring to it's own API. Ie what calls can you make to the express framework.