sentences:  The logical data structure of a database management system (DBMS), whether hierarchical, network, or relational, cannot totally satisfy the requirements for a conceptual definition of data because it is limited in scope and biased toward the implementation strategy employed by the DBMS.Therefore, the need to define data from a conceptual view has led to the development of semantic data modeling techniques.That is, techniques to define the meaning of data within the context of its interrelationships with other data.