DBMS (DataBase Management SystemA database management system is a complex set of software programs that control the organization, storage, and retrieval of fields, records, and files in a database. A DBMS also manages the security and integrity of a database. When an application program requests data, the DBMS accepts that request and instructs the operating system to transfer the applicable data.
A database system consists of four major components: data, hardware, software, and users. Conventional DBMS hardware consists of a secondary storage device (usually a hard disk), on which the database physically resides, together with associated I/O devices. A database can run on a range of systems, from a microcomputer to a large mainframe. It can also run on a database machine that is specifically designed to support a database system. All DBMSs will provide some data validation, such as rejecting invalid dates and letters entered in a numeric field, but more intelligent databases will perform other functions, such as correcting spelling errors and computing sales tax. The chief advantage of a DBMS is that it produces a logical and structured organization of data by imposing a formal structure on the data set. This makes data easier to manage, manipulate, and define. Although many DBMSs can manage both text and data, they don't always manage both effectively. But as storage capacities continue to grow larger, DBMSs will be able to handle text, voice, graphics, voice, and video with equal effectiveness.