The OAuth 2.0 Protocol
D. Recordon, Dick Hardt, Eran Hammer-Lahav · 2010
This specification describes the OAuth 2.0 protocol. OAuth provides a method for making authenticated HTTP requests using a token - an identifier used to denote an access grant with specific scope, duration, and other attributes. Tokens are issued to third-party clients by an authorization server with the approval of the resource owner. OAuth defines multiple flows for obtaining a token to support a wide range of client types and user experience.