Both Active Directory (AD) and Azure Active Directory (Azure AD) are directory services by Microsoft, but they serve different purposes, have different architectures, and are used in different environments.
Let’s dive into a detailed comparison based on key factors:
Windows Server licenses, Client Access Licenses (CALs)
Free tier; Premium P1/P2 for advanced features
Cost
Hardware, maintenance, software
Subscription-based, scalable
🔐 6️⃣ Security Features
Feature
Active Directory (AD)
Azure Active Directory (Azure AD)
Multi-Factor Authentication (MFA)
Not built-in (requires third-party solutions)
Built-in with Azure MFA
Conditional Access
Limited (via GPO, VPN)
Advanced Conditional Access policies
Identity Protection
On-premises tools
Azure AD Identity Protection (risk-based)
SSO
Primarily for Windows devices
SSO for thousands of cloud apps
🧠 7️⃣ Key Differences Summary
Feature
Active Directory (AD)
Azure Active Directory (Azure AD)
Where It Lives
On-premises (Windows Servers)
Cloud (Microsoft Azure)
Authentication Protocols
Kerberos, NTLM
OAuth, SAML, OpenID
Structure
Hierarchical (Domains, OUs)
Flat (no domains/OUs)
Device Management
GPOs, on-prem devices
Intune, Azure AD-joined
Use Case
Traditional networks
Cloud apps, hybrid/remote work
Access Management
On-prem resources
Cloud/SaaS resources
🚀 Conclusion
Active Directory is designed for on-premises IT environments, providing comprehensive device and user management for local resources.
Azure Active Directory is tailored for cloud-based identity and access management, enabling SSO, conditional access, and security for SaaS apps.
🔗 Many organizations use both, integrating them with Azure AD Connect for a hybrid identity solution, enabling seamless user experiences across on-prem and cloud.
