Microsoft Knowledge Base Article 915146 contains the following summary and introduction:
This article describes the Distributed File System (DFS) Management snap-in in Microsoft Windows Server 2003 R2.
You use DFS Management to manage DFS namespaces and DFS replication in the Microsoft Management Console (MMC).
When you use the DFS namespace and DFS replication together, these two technologies offer simplified, fault-tolerant access to files,
load sharing, and wide area network (WAN)-friendly replication.