Azure Active Directory

Azure Active Directory (Azure AD), now Microsoft Entra ID, is the definitive cloud-based Identity and Access Management (IAM) service: it secures all your users and applications.

Azure AD acts as your single control plane for identity, managing over 1.2 billion identities and handling 8 billion daily authentications (a massive scale). It is the backbone for Microsoft 365, Azure, and thousands of SaaS applications, providing critical Single Sign-On (SSO) capabilities. Administrators use it to enforce Zero Trust principles through Conditional Access policies and Multi-Factor Authentication (MFA), ensuring only verified users access resources. For hybrid environments, Azure AD Connect seamlessly synchronizes on-premises Active Directory identities to the cloud, maintaining a unified, secure experience across your entire enterprise footprint.

https://learn.microsoft.com/en-us/entra/identity/