On sso.tax, it states that "Single sign-on (SSO) is a mechanism for outsourcing the authentication for your website (or other product) to a third party identity provider, such as Google, Facebook, Okta, PingFederate, etc."
Isn't this the definition of Federation, rather than SSO?
As I understand it, federation enables two separate instances of some particular service to interact. They can still use single sign-on independently for their own authentication needs.
Isn't this the definition of Federation, rather than SSO?