Single Sign-On (SSO) is an authentication process that enables users to access multiple applications or systems with a single set of credentials, such as a username and password. Instead of requiring users to log in separately to each application, SSO allows them to authenticate once and gain access to all authorized resources seamlessly. This enhances user experience by reducing the need for multiple logins and simplifying the authentication process. Additionally, SSO improves security by centralizing user authentication and enforcing consistent access policies across different platforms or services.