Single Sign-On (SSO) is an important authentication solution that improves security and user satisfaction by offering simple, single sign-on access to all applications using a single sign-in. It alleviates password fatigue, decreases IT support costs, and enhances security policy compliance. SSO also makes user management simpler by centralizing the authentication process, thus streamlining onboarding and offboarding. SSO does, however, create a single point of entry, which has to be secured against unauthorized use. Organizations must reinforce SSO with Multi-Factor Authentication (MFA), session monitoring, and adaptive risk-based authentication to identify and thwart threats. When effectively used, SSO finds the right balance between convenience and robust security.