OpenID Connect (OIDC) is a modern federated identity protocol built on top of OAuth 2.0. It does roughly what SAML does — authenticate a user via an identity provider and pass identity assertions to a service provider — but uses JSON Web Tokens (JWTs) instead of XML, making it lighter and easier to implement.
OIDC is increasingly the default for new customer portal builds. It’s better-supported by modern frameworks and APIs, and the JWT-based design integrates cleanly with web and mobile applications. For B2B portals, supporting both SAML and OIDC is common — SAML for traditional enterprise customers, OIDC for newer or developer-focused customers.