A distributed database is a database in which portions of the database are stored on multiple computers within a network. Users have access to the portion of the database at their location so that they can access the data relevant to their tasks without interfering with the work of others.
Replicated database servers
Replication is the process of copying a database to another server, and then keeping the two copies in sync, so that they behave as near as possible. Replication copies data or changes of data from one database to another. Accessing the first database or the second, it does not matter because they are the same, i.e. they are in sync. Replication is not limited to two databases; any number of databases can take place into the replication model. With replication, maintenance of multiple copies of data to different locations is automated. Because each location has its one database, each location works essentially local with maximum performance and security; databases don't have to be accessed outside the local network or workstation.
Partitioned database servers