Azure Active Directory

Azure Active Directory is multi-tenant, cloud-based directory and identity management service. For an organization, Azure AD helps employees sign up to multiple services and access them anywhere over the cloud with a single set of login credentials.

It is cloud-based identity and access management service, which helps your employees sign in and access resources in:
1 - External resources, such as Microsoft 365, the Azure portal, and thousands of other SaaS applications.

2 - 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.