Single Sign-On (SSO) is an authentication process that allows users to access multiple applications with one set of login credentials. It enhances security by reducing password fatigue and minimizing the risk of weak passwords. SSO is commonly used in enterprise environments, integrating with identity providers like OAuth, SAML, and OpenID Connect. Businesses benefit from improved user experience and reduced IT support costs. However, it requires strong security measures, such as multi-factor authentication, to prevent unauthorized access. While SSO streamlines authentication, a compromised account can grant attackers access to multiple systems, making security best practices essential for its implementation.