OAuth vs. SSO vs. SAML
These get listed together as one 'auth' skill. SSO is the user experience: log in once, get into many apps. SAML and OpenID Connect are the protocols that make SSO work. OAuth is technically about letting one app act on your behalf in another (for example 'let this app read my Google Calendar'), which is authorization, not login, although OpenID Connect builds login on top of it.
How to tell them apart on a resume
SSO / SAML (enterprise login)
Okta, Entra ID (Azure AD), identity provider setup, onboarding enterprise customers, IT or security teams.
OAuth (delegated access)
API integrations, access tokens, 'Sign in with Google', connecting to third-party APIs. Usually backend developers.
The question that settles it
“Were you setting up company-wide login to many apps, or letting one app access another app's data on a user's behalf?”
Read the full definitions
Open the full tool for the other look-alike pairs, role profiles, and the JD decoder.