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Active Directory

AD

Active Directory (AD) is Microsoft's on-premises directory service that stores information about users, computers, and other network resources, providing authentication and authorization services across Windows enterprise environments.

IAM Microsoft Directory On-Premises

❓ What is Active Directory?

Active Directory (AD) is Microsoft's on-premises directory service that stores information about users, computers, and other network resources, providing authentication and authorization services across Windows enterprise environments.

⚙️ How Does It Work?

AD uses Kerberos for authentication and LDAP for directory queries. Users log in once (domain login) and receive a Kerberos ticket granting access to all domain resources their account is authorized to use.

📍 Where Is It Used?

On-premises Windows enterprise environments worldwide — still the identity backbone for the majority of large enterprises despite cloud migration trends.

💡 Real-World Example

A company with 20,000 employees uses Active Directory as its central identity store. Every employee login to a Windows PC, file server, or domain-joined application is authenticated against AD. Microsoft Entra ID sync extends these identities to the cloud.

🔗 Related Terms

Microsoft Entra ID LDAP Kerberos Directory Services SSO Domain Controller
← Agentic Access ManagementAPI Key →

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