SQL Server Replication allows database administrators to distribute data to various servers throughout an organization. Replication is the process of copying/moving data between databases on the same or different servers. SQL Server supports the following three types of replication scenarios:
1. Snapshot Replication: It acts in the manner its name implies. The publisher simply takes a snapshot of the entire replicated database and shares it with the subscribers.
2. Transactional Replication: It offers a more flexible solution for databases that change on a regular basis. With transactional replication, the replication agent monitors the publisher for changes to the database and transmits those changes to the subscribers. This transmission can take place immediately or on a periodic basis.
3. Merge Replication: It allows the publisher and subscriber to independently make changes to the database. Both entities can work without an active network connection. When they are reconnected, the merge replication agent checks for changes on both sets of data and modifies each database accordingly.