Glossary
Entra ID
By Emil Björk · Microsoft ecosystem consultant, Gothenburg
Microsoft's cloud identity and access service — the directory behind every Microsoft 365 sign-in.
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.
Worked example
A new employee's first day starts in Entra ID before they touch any app: HR creates the user object (or a Lifecycle Workflow does it automatically), group-based licensing assigns them a Microsoft 365 licence the moment they're added to the right group, and a Conditional Access policy decides whether their unmanaged personal laptop can reach Outlook at all, or only a browser-based limited view. None of that happens in Exchange, Teams, or SharePoint directly — those services all just check with Entra ID for who this person is and what they're allowed to do.
Common pitfalls
Treating Entra ID as "just the login screen" undersells it — it's also where licensing, group membership, device compliance signals, and every Conditional Access decision actually live, which is why so many unrelated-looking problems (a user can't open Teams, a report of "wrong" app access) trace back to an Entra ID group or policy. Confusing Entra ID with on-premises Active Directory Domain Services is a related and common mistake for admins coming from a traditional Windows Server background — they share naming conventions and some concepts, but Entra ID is a different product built for cloud and SaaS scenarios, not a hosted version of the same on-prem service. And still calling it "Azure AD" in scripts, documentation, or conversations two years after the rename can cause real confusion when a colleague searches current Microsoft documentation and can't find a match.