Identity Provider (IdP) & SSO platforms provide workforce authentication and federated single sign-on across an organization's application estate, and — when viewed through the security lens — act as the primary policy-enforcement point for authentication controls: MFA enforcement, adaptive and risk-based access, device-trust signals, and account-takeover detection. Core capabilities include federation protocol support (SAML 2.0, OIDC, SCIM), multi-factor and passwordless authentication, conditional-access policies tied to risk signals, session governance, continuous authentication, integration with identity-threat-detection tooling, and audit logging of every authentication event. Leading vendors include Okta, Microsoft Entra ID, Ping Identity, JumpCloud, and Google Workspace.