The term that is most likely part of the user authentication process when implementing SAML across multiple applications is SSO. SSO (Single Sign-On) is a way for users to be authenticated for multiple applications and services at once. With SSO, a user signs in at a single login screen and can then use a number of apps without having to enter their credentials again. SSO improves user experience and security by reducing password fatigue and phishing risks. SAML (Security Assertion Markup Language) is a protocol that enables SSO by providing a standardized way to exchange authentication and authorization data between an identity provider (IdP) and a service provider (SP). SAML uses XML-based messages called assertions to communicate user identity and attributes between parties.
Reference:
https://www.onelogin.com/learn/how-single-sign-on-works