Relational Database Management Systems - RDBMS
A relational DBMS is special system software that is used to manage the organization, storage, access, security and integrity of data. This specialized software allows application systems to focus on the user interface, data validation and screen navigation. When there is a need to add, modify, delete or display data, the application system simply makes a "call" to the RDBMS.
Although there are many different types of database management systems, relational databases are by far the most common. Other types include hierarchical databases and network databases.