Replication is the act of creating (normally automatically) a duplicate copy of a database or file system on a different computer. The term usually implies the intelligent copying of parts of the source database which have changed since the last replication with the destination.

Replication may be one-way or two-way. Two-way replication is much more complicated because of the possibility that a replicated object may have been updated differently in the two locations in which case some method is needed to reconcile the different versions.

Some examples:

  • Lotus Notes can automatically distribute document databases across telecommunications networks. Notes supports a wide range of network protocols including X25 and Internet TCP/IP.
  • LDAP (and implementations like ActiveDirectory) can be set up across multiple servers, so you query any one and get the same information, because they replicated between them.
  • PostgreSQL is getting replication in the next version.