Microsoft's Active Directory (AD) is a directory service for Windows domain networks that has become an umbrella term for diverse identity-related services. AD enables authentication and authorization, making it a crucial component of enterprise security. However, its on-premise version can be complex to manage, especially in large organizations with multiple users and permissions. A cloud-based version of Active Directory can simplify identity management by providing a centralized identity source and enhancing security through unified authentication and authorization. The three main AD-based solutions are Active Directory Domain Services (AD DS), Azure Active Directory (Azure AD), and Azure Active Directory Domain Services (Azure AD DS). Choosing the right version depends on the organization's specific needs, such as the level of control required over directory management, the need for legacy authentication services, and the complexity of the cloud deployment. A managed PaaS offering for AD DS can provide a convenient solution for organizations that don't require full control over directory management. Ultimately, selecting the right Active Directory solution is crucial for a smooth cloud migration and ensuring consistency with existing on-prem systems.