A database management system
, or DBMS
, is a piece of software
which allows you to create and access databases
. Most usually, a DBMS follows a client/server
model: the server
component, the DBMS program itself, manages the data on disk
and accepts connections from clients
which instruct it to store, query
, or modify data. Popular DBMS packages include PostgreSQL
, Microsoft SQL Server
, Microsoft Access
, and Oracle
Most of the well-reputed DBMS software today falls into the relational database management system, or RDBMS, category. An RDBMS is any DBMS that lets you create relational databases -- databases whose behavior is mathematically defined by certain axioms based on set theory. PostgreSQL, Microsoft SQL Server, Informix, and Oracle are all RDBMSes. Microsoft Access and FileMaker Pro are not relational. mySQL borders on being relational.
Most modern DBMSes -- including most of those mentioned above -- speak some dialect of IBM's Structured Query Language, or SQL.