Single Sign-On is when a user can use the same set of authentication credentials to access multiple different services.
- Single sign-on is a concept under Federated Identity Management. It solves the end user's problem of maintaining different sets of credentials for different web services
- With the help of an authentication token generated by an Identity Provider the user may access multiple different services in the same web session without re-entering his or her credentials for every service.
- One of the popular SSO standard is Security Assertion Markup Language which is the backbone of many SSO solutions present in the market.
- Many big players like Facebook, google and yahoo also provide Federated Identity services