O365 Admin

Entra ID vs Active Directory: What Is the Difference?

Published 9 October 2025 · 7 min read

Entra ID and Windows Server Active Directory are often confused but are fundamentally different products that solve different problems. This guide explains what each does, how they relate, and which you need.

What is Active Directory

Active Directory (AD) is an on-premises directory service for Windows networks. It manages domain-joined computers, Kerberos authentication, Group Policy, and on-premises resources. It requires domain controllers running Windows Server on-premises or in a hosted data centre.

What is Entra ID

Entra ID is Microsoft cloud identity platform. It manages Microsoft 365 authentication, SSO to SaaS applications, Conditional Access, device management via Intune, and external identities. No servers to manage - it is a service.

Key differences

📊
Active Directory vs Entra ID
Infrastructure
On-premises servers required vs Cloud service - no servers
Protocols
Kerberos, LDAP, NTLM vs OAuth, OpenID Connect, SAML
Device join
Domain join vs Entra ID join
Policy management
Group Policy vs Intune + Settings Catalog
Authentication target
On-prem apps vs Cloud apps, M365, SaaS

Which do I need?

📊
Which identity system?
New business, no on-premNo AD required for cloud-first
Entra ID only
Existing AD moving to M365Use Entra Connect to sync
Hybrid - both AD and Entra ID
On-premises apps using KerberosThese require domain controllers
Keep AD on-premises
All apps cloud/SaaSMigration project to remove AD
Entra ID only achievable

Frequently Asked Questions

Q: Is Entra ID a replacement for Active Directory?

For cloud-first organisations yes. But if you have on-premises apps that rely on Kerberos, LDAP, or domain join, you still need on-premises AD.

Q: Can I use Intune without Active Directory?

Yes. Intune works entirely with Entra ID. Devices enrol via Entra ID join. No on-premises AD required.

Q: What is Entra Domain Services?

A Microsoft-managed AD-compatible service in Azure providing Kerberos and LDAP without you running domain controllers.

Related Guides
-> Intune vs Group Policy-> Set Up Intune for Small Business-> Zero Trust for Small Business
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