Two or more servers are configured in a cluster arrangement to operate
as a "virtual" SQL server. Each server has software locally installed AND also installed via a shared sub-system with the other servers in the
cluster.
A "heartbeat" is heard between servers in the cluster, ensuring each
server is functioning properly; if not, then "Failure" Occurs - i.e if one machine in the cluster fails, another assumes the responsibilities of the downed server thus the hardware failure does not result in loss of functionality for the application. (Voyager)

Provisions of SQL-Server Replication.
Remote users can make updates independently, without requiring access to the Central Server. Data conflict handling - prevents corruption if two records are modified simultaneously from different locations.
Specified data e.g. pricing, can be restricted to central control.
Synchronization occurs both "on-demand" and on a scheduled basis and is possible via internet. We include optional intermediate layers such as regional servers for large corporate practices.