It stands for Relational Data Base Management System. It is data stored in a set of related tables. There are other objects like queries, views, indexes, clusters, etc in a RDBMS. It is used to store millions of transactions or records in transaction intensive industries like the BFSI, BPO etc. Popular RDBMS providers are Oracle, SQL Server from Microsoft, Sybase, Ingres et al. SQL Server 2005 edition has built in data warehousing, mining and Business Intelligence and Analysis functions and tools built into it.