Entra ID

Microsoft Entra ID is Microsoft's cloud identity and access management service. It's the directory of users, groups, and devices that sits behind every Microsoft 365 sign-in, and it's the system that decides who can access which apps and data.

Entra ID was previously called Azure Active Directory (Azure AD); Microsoft renamed it in 2023. Beyond signing users into Microsoft 365, it provides single sign-on to thousands of third-party SaaS apps, multi-factor authentication, conditional access policies, and B2B/B2C scenarios for partners and customers. If a Microsoft 365 admin talks about "users," "groups," or "tenants," they're almost always talking about Entra ID objects.