RDBMS is the abbreviation for Relational Database Management System and is pronounced as separate letters, a type of database management system (DBMS) that stores data in the form of related tables. Relational databases are powerful because they require few assumptions about how data is related or how it will be extracted from the database. As a result, the same database can be viewed in many different ways.
An important feature of relational systems is that a single database can be spread across several tables. This differs from flat-file databases, in which each database is self-contained in a single table. Almost all full-scale database systems are RDBMS's. Small database systems however, use other designs that provide less flexibility in posing queries.
From a technical standpoint, DBMSs can differ widely. In addition to the relational DBMS, there are also network, flat, and hierarchical DBMS's. These all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information.
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