Single Sign-On (SSO) is a centralized authentication process that enables users to access multiple applications, systems, or platforms with a single set of credentials. Instead of requiring users to remember and enter distinct usernames and passwords for each application, SSO allows them to log in once and gain access to all authorized resources seamlessly. 

Rebrandly is not a provider of SSO and only supports Security Assertion Markup Language 2.0 (SAML 2.0).