Single sign-on (SSO) is an authentication process that allows users to access multiple applications with one set of login credentials. This significantly enhances user convenience and reduces the need to remember multiple usernames and passwords. SSO works by establishing a central login system that verifies the user's identity once and grants access to all connected systems. Technologies like OAuth and SAML facilitate this process by managing secure token exchanges. By reducing login friction, SSO helps improve security and user satisfaction across enterprise applications.