A Sync Pipe defines a single synchronization path between the source and destination targets. One Sync Pipe is needed for each point-to-point synchronization path defined for a topology.

Sync Source
Determine which external server is the Sync Source for the synchronization topology. A prioritized list of external servers can be defined for failover purposes.
Sync Destination
Determine which external server is the Sync Destination for the synchronization topology. A prioritized list of external servers can be defined for failover purposes.