SAML

Security Assertion Markup Language

XML-based standard for federated identity / SSO between IdP and SP.

When you'd see it: Enterprise single sign-on setups. SAML is how many corporate apps trust one central identity provider.

Why it matters: SAML lets a company use one login to grant access to many applications, the backbone of enterprise SSO. It predates OAuth and still dominates inside large organizations.

Common mistakes: Confusing SAML (enterprise SSO, XML-based) with OAuth (authorization, token-based). They overlap in use but solve different problems.