• Password hash synchronization - A sign-in method that synchronizes a hash of a users on-premises AD password with Azure AD.
• Pass-through authentication - A sign-in method that allows users to use the same password on-premises and in the cloud, but doesn't require the additional infrastructure of a federated environment.
• Federation integration - Federation is an optional part of Azure AD Connect and can be used to configure a hybrid environment using an on-premises AD FS infrastructure. It also provides AD FS management capabilities such as certificate renewal and additional AD FS server deployments.
• Synchronization - Responsible for creating users, groups, and other objects. As well as, making sure identity information for your on-premises users and groups is matching the cloud. This synchronization also includes password hashes.
• Health Monitoring - Azure AD Connect Health can provide robust monitoring and provide a central location in the Azure portal to view this activity.

Integrating your on-premises directories with Azure AD makes your users more productive by providing a common identity for accessing both cloud and on-premises resources. Users and organizations can take advantage of:

• Users can use a single identity to access on-premises applications and cloud services such as Microsoft 365.
• Single tool to provide an easy deployment experience for synchronization and sign-in.

Provides the newest capabilities for your scenarios. Azure AD Connect replaces older versions of identity integration tools such as DirSync and Azure AD Sync.