Azure Active Directory is a service that provides identity and access management capabilities in the cloud. In much the same way that Active Directory is a service made available to customers through the Windows Server operating system for on-premises identity management, Azure Active Directory (Azure AD) is a service that is made available through Azure for cloud-based identity management. Learn more
Because it is your organization's cloud directory, you decide who your users are, what information to keep in the cloud, who can use the information or manage it, and what applications or services are allowed to access that information.
When you use Azure AD, it is Microsoft's responsibility to keep Active Directory running in the cloud with high scale, high availability, and integrated disaster recovery, while fully respecting your requirements for the privacy and security of your organization's information.
Integration with your on-premises Active Directory
Azure AD can be used as a standalone cloud directory for your organization, but you can also integrate existing on-premise Active Directory with Azure AD. Some of the features of integration include directory sync and single sign-on, which further extend the reach of your existing on-premises identities into the cloud for an improved admin and end user experience. Learn more
Integration with your applications
Application developers can integrate their applications with Azure AD to provide single sign-on functionality for their users. This enables enterprise applications to be hosted in the cloud and to easily authenticate users with corporate credentials. It also enables software as a service (SaaS) providers to make authentication easier for users in Azure AD organizations when authenticating to their services. Developers can also use the Graph API to query directory data for managing entities such as users or groups. Learn more