Replication is a set of technologies for copying and distributing
data and database objects from one database to another and then
synchronizing between databases to maintain consistency. Using
replication, you can distribute data to different locations and to
remote or mobile users over local and wide area networks, dial-up
connections, wireless connections, and the Internet.
Transactional replication is typically used in
server-to-server scenarios that require high throughput, including:
improving scalability and availability; data warehousing and reporting;
integrating data from multiple sites; integrating heterogeneous data;
and offloading batch processing. Merge replication is primarily designed
for mobile applications or distributed server applications that have
possible data conflicts. Common scenarios include: exchanging data with
mobile users; consumer point of sale (POS) applications; and integration
of data from multiple sites. Snapshot replication is used to provide
the initial data set for transactional and merge replication; it can
also be used when complete refreshes of data are appropriate. With these
three types of replication, SQL Server provides a powerful and flexible
system for synchronizing data across your enterprise.
As an alternative to replication, you can synchronize
databases by using Microsoft Sync Framework. Sync Framework includes
components and an intuitive and flexible API that make it easy to
synchronize among SQL Server, SQL Server Express, SQL Server Compact,
and SQL Azure databases. Sync Framework also includes classes that can
be adapted to synchronize between a SQL Server database and any other
database that is compatible with ADO.NET. For detailed documentation of
the Sync Framework database synchronization components, see Synchronizing Databases. For an overview of Sync Framework, see Microsoft Sync Framework Developer Center. For a comparison between Sync Framework and Merge Replication, see Synchronizing Databases Overview'
ref..................http://msdn.microsoft.com/en-us/library/ms151198.aspx