---
Title: "What Is Single Sign-On (SSO)? How It Works"
Url: "https://computer.io/glossary/single-sign-on"
Topic: "Data and security"
Description: "Single sign-on (SSO) lets users log in once and access many apps without separate passwords. How SSO works, protocols like SAML and OIDC, and benefits."
---

# What is single sign-on (SSO)?

Single sign-on (SSO) is an authentication method that lets users log in once with one set of credentials and access multiple applications without signing in again. An identity provider verifies the user and passes a trusted token to each app using protocols like SAML or OpenID Connect.

## How it works

1. User opens an app.
2. App redirects to the identity provider.
3. User signs in (often with MFA).
4. Identity provider sends a token.
5. App grants access.

## Protocols

| Protocol | Common use |
| --- | --- |
| SAML | Enterprise web apps |
| OpenID Connect | Modern web and mobile |
| OAuth 2.0 | Authorization for APIs |

## Benefits

Fewer passwords, central control and faster offboarding.

## FAQ

### Is SSO secure?

Yes, especially with MFA, though the identity provider becomes critical.

### What is an identity provider?

A service like Okta or Entra ID that verifies users.

### Do AI agents use SSO?

Agents often act using the user's identity and permissions via SSO-linked tokens.

## Related terms

- [SCIM](https://computer.io/glossary/scim)
- [Role-based access control (RBAC)](https://computer.io/glossary/role-based-access-control)
- [Permission-aware AI](https://computer.io/glossary/permission-aware-ai)

## How Computer helps

- [Pricing](https://computer.io/pricing)

## Further reading

- [Scim advantage](https://devrev.ai/blog/scim-advantage)