Active Directory Services

Active Directory Domain Services (AD DS) is a Windows Server role that provides authentication and authorization services for the organization’s users and devices, line-of-business applications, third-party applications, server-based desktops, and on-premises installations of Microsoft applications, such as Exchange Server. For devices joined to a domain, AD DS enables identity and access management (IAM), including single sign-on (SSO) to resources in the domain, administrative password reset, and password policy enforcement. AD DS can be deployed on-premises or in Azure VMs.

Azure Active Directory (AAD, sometimes called Azure AD) is a Microsoft-hosted directory service that provides identity and access management for Microsoft 365, Intune, and most other Microsoft online services. Paid tiers of AAD are a part of the Enterprise Mobility + Security (EMS) and Microsoft 365 suites of hosted services. The service authenticates users, manages user account information, and offers self-service password reset and multifactor authentication (MFA). Premium editions of the service add capabilities for management of users, including reporting and security oversight.