OAuthAn authorization framework — lets apps access user data without sharing passwords. 1.0 let users grant third-party apps limited access to services like photos or tweets using signed requests instead of handing over credentials. Twitter, Flickr, and early social APIs adopted it. The three-legged dance (request token, authorize, access token) was clunky but proved delegated authorization could work at web scale — setting the stage for OAuthAn authorization framework — lets apps access user data without sharing passwords. 2.0 and OpenID ConnectAn identity layer on OAuth 2.0 — standardized login with ID tokens and user profiles..

OAuthAn authorization framework — lets apps access user data without sharing passwords. 1.0 was the first grassroots standard for APIApplication programming interface — a defined way for programs to talk to each other or to a service. delegation across competing web platforms.

It established the consent-and-token model that modern identity federation still builds on.