Azure Active Directory (Azure AD) Cloud Sync is a feature of Microsoft Azure that enables organizations to synchronize their on-premises Active Directory identities with their Azure Active Directory identities. The goal of Azure AD Cloud Sync is to provide a single identity solution that enables users to access both on-premises and cloud-based resources with a single set of credentials.

With Azure AD Cloud Sync, organizations can synchronize their on-premises Active Directory data to Azure AD in the cloud, and keep the data in sync over time. This helps organizations to maintain a consistent view of their users, groups, and devices, regardless of where their resources are located.

The Azure AD Cloud Sync feature is based on the Azure AD Connect tool, which is a free and easy-to-use tool that enables organizations to synchronize their on-premises Active Directory data with Azure AD. The Azure AD Connect tool supports several synchronization options, including password hash synchronization, pass-through authentication, and federation.

Once the on-premises Active Directory data is synchronized with Azure AD, organizations can use Azure AD to manage their identities, including the creation and management of user accounts, groups, and devices. They can also leverage Azure AD to enforce security and compliance policies, such as multi-factor authentication, conditional access, and identity protection.

Overall, Azure AD Cloud Sync is a powerful tool that enables organizations to integrate their on-premises and cloud-based identities, and provides a simple and secure way to manage identities in the cloud.