Single Sign-On (SSO) is an authentication mechanism that allows users to access multiple applications and services with a single set of credentials and one login event. SSO is typically implemented using protocols such as SAML, OAuth 2.0 or OpenID Connect, with an identity provider managing the authentication process and issuing tokens or assertions to participating service providers.
SSO improves both user experience and security by reducing password fatigue and the likelihood of credential reuse across services. From a compliance perspective, SSO centralises authentication logging and simplifies access reviews, making it easier to enforce consistent policies such as multi-factor authentication across the entire application estate.