What is the protocol used by Facebook for Authenticating and authoring third party resources?

This explains about the new protocol the Facebook uses to Authenticate and Authorize the third party resource.

Facebook uses OAuth 2.0 protocol for authentication and authorization of third party resources from within Facebook.

OAuth which stands for Open Authorization is open standard for authorization which is used to share the private resources like images, videos across different sites without really passing the user credentials in between the sites. OAuth instead of passing User credentials (like Username and password) it hands out token.