Azure Active Directory

Azure Active Directory (Azure AD) is Microsoft’s cloud-based identity and access management service, which helps your employees sign in and access resources in:

External resources, such as Microsoft Office 365, the Azure portal, and thousands of other SaaS applications.
Internal resources, such as apps on your corporate network and intranet, along with any cloud apps developed by your own organization. For more information about creating a tenant for your organization, see Quickstart: Create a new tenant in Azure Active Directory.

To learn the difference between Azure AD and Active Directory Domain Services, see Compare Active Directory to Azure Active Directory. You can also use the various Microsoft Cloud for Enterprise Architects Series posters to better understand the core identity services in Azure, Azure AD, and Office 365.

Who uses Azure AD?

Azure AD is intended for:

IT admins. As an IT admin, you can use Azure AD to control access to your apps and your app resources, based on your business requirements. For example, you can use Azure AD to require multi-factor authentication when accessing important organizational resources. Additionally, you can use Azure AD to automate user provisioning between your existing Windows Server AD and your cloud apps, including Office 365. Finally, Azure AD gives you powerful tools to automatically help protect user identities and credentials and to meet your access governance requirements. To get started, sign up for a free 30-day Azure Active Directory Premium trial.
App developers. As an app developer, you can use Azure AD as a standards-based approach for adding single sign-on (SSO) to your app, allowing it to work with a user's pre-existing credentials. Azure AD also provides APIs that can help you build personalized app experiences using existing organizational data. To get started, sign up for a free 30-day Azure Active Directory Premium trial. For more information, you can also see Azure Active Directory for developers.
Microsoft 365, Office 365, Azure, or Dynamics CRM Online subscribers. As a subscriber, you're already using Azure AD. Each Microsoft 365, Office 365, Azure, and Dynamics CRM Online tenant is automatically an Azure AD tenant. You can immediately start to manage access to your integrated cloud apps.