Active Directory vs Entra ID: What Actually Changes
Active Directory is an on-premises directory service that authenticates users against domain controllers on your network. Entra ID (formerly Azure AD) is Microsoft's cloud-based identity platform that authenticates users from anywhere, with no servers required. The practical difference: AD trusts your network perimeter; Entra ID verifies every sign-in individually using Conditional Access, MFA, and device state — which is why it's the foundation of Zero Trust security.
- Domain controllers disappear entirely — no more patching, replication issues, or FSMO roles
- Group Policy is replaced by Intune configuration profiles (most GPOs have a direct equivalent)
- Devices join Entra ID directly instead of the domain, enabling Autopilot provisioning
- Kerberos/NTLM legacy authentication gives way to modern protocols (OAuth 2.0, SAML)
- Conditional Access replaces "inside the firewall = trusted" with per-sign-in risk evaluation
The migration path matters as much as the destination. Most organizations pass through a hybrid phase with Entra Connect syncing identities — the mistake is treating hybrid as the end state instead of a transition. The full article covers the staged cutover sequence, which AD dependencies actually block a move, and how to retire your last domain controller without breaking legacy applications.
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