OAuth2 Basics and Social Login Integration
OAuth2 is an authorisation framework that allows a user to grant your application access to their data on another service (Google, GitHub, Facebook) without sharing their password. OpenID Connect (OIDC) builds on OAuth2 to provide identity — the ID token tells you who the user is. Spring Security has first-class support for both as a client (social login) and as a resource server (validating tokens from an authorisation server).