Single sign-on (SSO) is an authentication method that allows users to access multiple applications or systems with a single set of login credentials. Once authenticated, users can navigate between various services without needing to re-enter their username and password for each one. SSO improves user convenience and productivity by reducing the number of logins required while also enhancing security through centralized authentication and reduced password fatigue. It simplifies user management for administrators and supports consistent access control policies across an organization’s IT environment.