TL;DR:

Single sign-on (SSO) is like having a master key that unlocks multiple doors. Instead of remembering different keys (passwords) for each door (application or website), you only need one. When you log in once, SSO checks if you’re already authenticated and grants you access to all the doors you need. This makes it easier and more secure for you, as you don’t have to juggle multiple passwords. However, if someone gets hold of your master key, they can access everything, so it’s crucial to keep it safe.

Details for the Techies

Single sign-on (SSO) is a user authentication method that allows users to access multiple applications and websites with one set of credentials. It works by establishing a trust relationship between an application and an identity provider. When a user logs in to an application, the identity provider checks if the user has already been authenticated. If so, the identity provider sends a token back to the application to confirm authentication, granting the user access.

SSO improves security and user experience by reducing the need for users to remember and manage multiple passwords. It also helps meet compliance standards such as SOC 2 and HIPAA. Many popular social media services, including Google, LinkedIn, Twitter, and Facebook, offer SSO services. However, social SSO can pose a security risk because it creates a single point of failure that attackers can exploit.

For more detailed information, you can refer to the SSO page on Wikipedia.