What is V in API?

Excuse me, but could you please clarify for me what exactly is meant by "V" in the context of an API? Is it a specific programming language, a version number, or perhaps a reference to a certain type of data or functionality within the API? I'm quite intrigued to understand the specifics of this terminology and how it relates to the broader world of APIs. Could you provide a brief explanation or perhaps an example to help me grasp the concept better?