A Distributed Database Management System is a software system that permits the management of a distributed database and makes the distribution transparent to the users.
A distributed database is a collection of multiple, logically interrelated databases distributed over a computer network.
Sometimes "distributed database system" is used to refer jointly to the distributed database and the distributed DBMS.
Client server DBMS
The Client--Server DBMS Model has emerged as the main paradigm in database computing.
The Enhanced Client--Server architecture takes advantage of all the available client resources including their disk managers.
However, when updates occur at the server, some of the client data managers may need to not only be notified about them but also obtain portions of the updates as well.
An object-relational database (ORD) or object-relational database management system (ORDBMS) is a relational database management system that allows developers to integrate the database with their own custom data types and methods.
The term object-relational database is sometimes used to describe external software products running over traditional DBMSs to provide similar features; these systems are more correctly referred to as object-relational mapping systems.
In an object oriented database, information is represented in the form of objects as used in Object-Oriented Programming. When database capabilities are combined with object programming language capabilities, the result is an object database management system (ODBMS).
An ODBMS makes database objects appear as programming language objects in one or more object programming languages.
An ODBMS extends the programming language with transparently persistent data, concurrency control, data recovery, associative queries, and other capabilities.