Single sign-on means one trusted account confirms your identity for other apps. It is the idea behind Sign in with Google, Continue with Apple, Microsoft sign-in buttons, and many workplace login systems.
Does this affect you?
Use this if you see SSO or social sign-in buttons on apps and websites, or if your job uses one company login for email, chat, files, and internal tools.
What happens when you click Sign in with Google
The app does not receive your Google password. It receives a confirmation token.
- You click Sign in with Google, Apple, Microsoft, Facebook, or a similar button.
- The app redirects you to that provider’s own sign-in page.
- You confirm your identity there, often because you are already signed in on the device.
- The provider shows what information the app wants, usually name, email address, and profile photo.
- After you approve, the provider sends the app a secure token confirming who you are.
- The app trusts that token instead of creating and storing a separate password for you.
Workplace SSO works the same way
At work, your company account becomes the identity provider.
- Your employer may use Microsoft 365, Google Workspace, Okta, Microsoft Entra ID, or another identity platform.
- You sign in once to the company account, then connected tools recognize that login.
- IT can require MFA, device checks, or password rules in one place.
- When someone leaves the company, IT can disable the central account and cut off connected app access quickly.
More control
Review connected apps
Google, Apple, Microsoft, and other providers let you see which apps are connected. On Google, check myaccount.google.com > Security > Third-party apps with account access. On Apple, check Settings > your name > Sign-In & Security > Apps Using Apple ID.
Protect the central account
The convenience of SSO is also the risk: losing Google, Apple, Microsoft, or your work account can affect every app that depends on it. Use a strong password and multi-factor authentication.
SSO is not a password manager
A password manager stores separate passwords for separate accounts. SSO removes the separate password and lets one identity provider vouch for you instead.
Sources
- Microsoft Support – What is Single Sign-On SSO? (2025)
- Google Safety Center – Sign in with Google (2025)
- CISA – Identity and access management (2025)