Comparing Windows Server Active Directory and Azure Active Directory

Windows Server Active Directory (AD) and Azure Active Directory (Azure AD) share a common heritage and name and both play an important role in Microsoft’s identity management services, but there are significant differences between them. The following chart details the main differences between Windows Server AD and Azure AD.

Windows Server AD is the authentication and authorization service for most of an organization’s infrastructure, including the organization’s devices, line-of-business applications, third-party applications, and on-premises installations of Microsoft applications, such as Exchange.

Azure AD is a multitenant, Microsoft-hosted service, designed to work with a variety of hosted applications from Microsoft and third parties, as well as with other private and public identity providers.

Windows Server AD can also run in Azure-hosted virtual machines (VMs). However, in this configuration, each organization manages all AD servers (domain controllers) and their underlying Windows Server OS installations. With Azure AD, in contrast, Microsoft manages the underlying infrastructure, leaving the customer organization to manage only its users, groups, and other directory data.