> The OpenAPI Specification, previously known as the Swagger Specification
is a specification for a machine-readable interface definition language for
describing, producing, consuming and visualizing web services.
Oh, forgot to mention that definition is a quote from the Wikipedia page about OpenAPI.
I found the name weird, since I'm only used to open API. It's when your mode of access is obscured, like poking physical hardware, or triggering code through HTTP or other generic protocols, that one needs to actively describe the API to make it "open".
> The OpenAPI Specification, previously known as the Swagger Specification is a specification for a machine-readable interface definition language for describing, producing, consuming and visualizing web services.