I get a ton of emails asking me exactly how ESRI’s geodatabase replication works. It is pretty slick to be honest so I think everyone who has SDE should probably learn more about it. ESRI has posted a podcast titled “Geodatabase Replication: Working with Replication that explains in more detail what geodatabase replication is.
Geodatabase replication enables the distribution of datasets across several geodatabases, and provides a mechanism for keeping those datasets in synch by sending changes over the network or the Internet. This discussion contains suggestions for planning a replication strategy that will help you implement a comprehensive distributed data workflow. The mechanics of creating and synchronizing replicas are also discussed.