OpenID Connect (OIDC) is an authentication layer built on top of the OAuth 2.0 protocol. While OAuth 2.0 is primarily designed for authorization, OIDC extends its capabilities to provide a standardized way for systems to verify the identity of users. OIDC adds an identity token (usually in the form of a JSON Web Token or JWT) to the OAuth 2.0 process. This token contains claims about the authentication event and the user, such as the user's identity, when they were authenticated, and how. OIDC simplifies the implementation of single sign-on (SSO) across multiple applications and domains. It's widely adopted by major identity providers and is particularly useful in cloud and mobile scenarios where traditional authentication methods may be less suitable.
