Single Sign-On (SSO)

Single sign-on (SSO) lets someone authenticate once against a central system and then move among multiple connected services without re-entering credentials at each one. Log into your work account in the morning, and email, calendar, and a dozen internal tools all let you in.

For a web project, SSO usually shows up as an integration: your site hands authentication off to an existing identity system rather than maintaining its own logins. It's convenient for users and, done right, more secure, since there is one central system to guard rather than many separate ones.