What is Microsoft Entra ID? A plain-English explainer
Microsoft Entra ID is Microsoft’s cloud-based identity and access management service — the system that manages who a user is and what they are allowed to access across Azure, Microsoft 365 and other connected applications. If that description sounds familiar, it should: Entra ID is the same service that used to be called Azure Active Directory, or Azure AD, and Microsoft renamed it as part of a broader Entra product family covering identity and access. The renaming did not change what the service does — it is the same identity platform, under a new name. Because both names are still searched for and both still appear across older documentation, training material and job listings, it is worth being explicit about the rename before anything else. Here is what identity and access management is, what Entra ID actually does, and why it sits at the centre of Azure security.
The rename, stated plainly
Microsoft Entra ID was formerly known as Azure Active Directory (Azure AD). The service, its capabilities and its role in Azure did not fundamentally change — Microsoft renamed it as it consolidated several identity and network access products under the “Entra” brand. If you see “Azure AD” in older material, or hear someone refer to it that way in conversation, it means the same service this article is describing.
This matters practically because search results, documentation and even exam material from different points in time use both names. Knowing they refer to the same thing avoids real confusion, particularly for anyone studying from a mix of older and newer resources.
What identity and access management is
Identity and access management (IAM) is the discipline of controlling who — a person, an application, or a device — can prove who they are, and what they are then allowed to do. Every cloud platform needs an answer to both halves of that question: authentication (are you who you say you are) and authorisation (what are you allowed to access, now that you have proven it). Our what-is-identity-and-access-management explainer covers the concept in general; Entra ID is Microsoft’s implementation of it for Azure and the wider Microsoft ecosystem.
Without a system like this, every application would need to build and maintain its own list of users and passwords — duplicated, inconsistent, and a security risk every time someone leaves an organisation and their access is not revoked everywhere at once. A central identity service exists precisely to avoid that.
What Entra ID actually does
Entra ID is where an organisation’s users and groups live in the cloud, and it is the service that handles signing them in. Its core capabilities, conceptually, are:
- User and group management — a central directory of identities and the groups that organise them for access purposes.
- Single sign-on (SSO) — signing in once with an Entra ID identity to access many connected applications, rather than a separate login for each one.
- Multi-factor authentication (MFA) — requiring more than a password to sign in, adding a second proof of identity such as a code or approval on a device.
- Conditional access — applying access rules based on context, such as requiring extra verification when a sign-in looks unusual, rather than treating every sign-in attempt identically.
How Entra ID relates to on-premises Active Directory
Despite the shared word “Active Directory” in its former name, Entra ID is not simply Active Directory moved to the cloud. Traditional Active Directory (often called Active Directory Domain Services) is a system designed to manage identities within a single organisation’s own network, using protocols built for that on-premises world. Entra ID is a cloud-native identity service built around modern, internet-facing authentication standards, designed for signing into cloud applications from anywhere.
The two can work together — an organisation with an existing on-premises Active Directory can synchronise its identities into Entra ID, so the same accounts work in both worlds during a migration or in an ongoing hybrid setup. But they are distinct products solving related problems in different environments, not one simply being a copy of the other.
Why it is central to Azure and Microsoft 365 security
Entra ID underpins security across the whole Microsoft cloud ecosystem, not just Azure. Signing into Microsoft 365, managing who can administer Azure resources, and controlling which applications a user’s account can reach all route through it. Because it is the single front door for identity, weaknesses there — a weak password policy, no multi-factor authentication — have consequences far beyond any one application.
That centrality is exactly why identity is treated as a foundational security topic rather than an optional add-on across Microsoft’s certification and security guidance: get identity right, and a large share of common attack paths close with it.
Where Entra ID appears in certification study
Identity is core content across the Azure certification path. Azure Fundamentals (AZ-900) introduces Entra ID conceptually as part of Azure’s security and governance model. Azure Administrator Associate (AZ-104) dedicates a full domain to identity — managing users, groups, and access using Entra ID is a core administrative responsibility the exam tests directly. Identity and access management concepts also appear in vendor-neutral security study, such as the ISC2 Certified in Cybersecurity certification.
This article covers what Entra ID is and why it exists — configuring conditional access policies, MFA methods and hybrid identity in detail belongs in the syllabus itself, which our /revision study library breaks down lesson by lesson for these certifications.
Original practice questions, timed mock exams and revision notes. No card, nothing to pay.