About transactional replication
In transactional replication, all changes on both the source database and the target
database are committed or rolled back together. Transactional replication assumes that the
source location and the target location are always connected through SQL Server and have the
same database schema (same application version). It also requires that the source and target
be associated with different sites.
Transactional replication allows immediate updates between databases without the use of queues or XML-formatted content. The system uses only database triggers and direct stored procedure calls to replicate the data.
This means that the system catches data errors immediately (for example, requesting an item that does not exist at the specified remote location). In this case, the system does not allow the user to save the record with the error.
For best performance, both databases should be on SQL Server machines within the same LAN, or even on the same SQL Server machine.