Database replication is used to ensure consistency between redundant databases and to improve reliability and increase fault-tolerance. The replication process commonly involves continuously duplicating a "master" database to one or more additional "slave" databases.
Database replication can be used on many database management systems, usually with a master/slave relationship between the original and the copies. The master logs the updates, which then ripple through to the slaves. The slave outputs a message stating that it has received the update successfully, thus allowing the sending (and potentially re-sending until successfully applied) of subsequent updates.
