(DATABASE 2) A relational DBMS from IBM that was originally developed for its mainframes. Introduced in 1983, DB2 is a full-featured SQL-based DBMS that became IBM's major database product. Known for its industrial strength reliability, IBM subsequently made DB/2 available for all of its own platforms as well as Linux, Unix (Solaris, HP-UX) and Windows.DB2 UDB (Universal Database)In 1996, IBM introduced an enhanced DB2 version that combined relational and object database technology as well as various query optimization techniques for parallel processing. It was also the first DB2 version optimized for the Web. The terms "DB2" and "DB2 UDB" are used synonymously.