Active Directory Replication Versus FRS Replication

Active Directory is a distributed directory service. Objects in the directory are distributed across the domain controllers in a forest, and all domain controllers in a domain
can be updated directly, this is known as multimaster. Replication is the process by which the changes that are made on one domain controller are synchronized with all other domain controllers in the domain or forest that store copies of the same information. Data integrity is maintained by tracking changes on each domain controller and updating other domain controllers in a systematic way.

Active Directory replication uses a connection topology that is created automatically, which makes optimal use of beneficial network connections and frees the administrators from having to make such decisions.

The word, replication, is used to describe Active Directory replication and file replication.

These are two separate entities.

FRS is a multimaster replication service that is used to replicate files and folders in the System Volume (SYSVOL) shared folder on domain controllers and in Distributed File System (DFS) shared folders. FRS works by detecting changes to files and folders and then replicating the updated files and folders to other replica members, which are connected in a replication topology.

FRS uses the replication topology that is generated by the KCC to replicate the SYSVOL files to all domain controllers in the domain. SYSVOL files are required by all domain controllers for Active Directory to function