The latest version is:
The Graph API is the primary way for apps to read and write to the Facebook social graph. All of our SDKs and products interact with the Graph API in some way, and our other APIs are extensions of the Graph API, so understanding how the Graph API works is crucial.
If you are unfamiliar with the Graph API, we recommend that you start with these documents:
Learn how the Graph API is structured, what access tokens are, and how versions work.
Learn how to perform common operations.
Learn how to build queries and receive responses from the Graph API with our Graph API Explorer app.
Learn how to read our reference documents so you can easily find what you're looking for.
Once you're familiar with the basics, you can move on to more advanced topics like the ones below: