What is OAuth/OIDC?

OAuth (Open Authorization) is an open standard authorization protocol that enables secure delegated access. It allows users to grant a third-party application limited access to their resources on a service (like Facebook or Google) without sharing their credentials. OIDC (OpenID Connect) is an identity layer built on top of OAuth 2.0. It allows clients to verify the identity of the end-user based on the authentication performed by an authorization server, as well as to obtain basic profile information about the end-user in an interoperable and REST-like manner. OIDC is commonly used for single sign-on (SSO) solutions and user authentication.