<P> 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 . As illustrated in the figure . The real world, in terms of resources, ideas, events, etc., are symbolically defined within physical data stores . A semantic data model is an abstraction which defines how the stored symbols relate to the real world . Thus, the model must be a true representation of the real world . </P> <P> Data architecture is the design of data for use in defining the target state and the subsequent planning needed to hit the target state . It is usually one of several architecture domains that form the pillars of an enterprise architecture or solution architecture . </P> <P> A data architecture describes the data structures used by a business and / or its applications . There are descriptions of data in storage and data in motion; descriptions of data stores, data groups and data items; and mappings of those data artifacts to data qualities, applications, locations etc . </P> <P> Essential to realizing the target state, Data architecture describes how data is processed, stored, and utilized in a given system . It provides criteria for data processing operations that make it possible to design data flows and also control the flow of data in the system . </P>

What are three terms used to describe the levels of database architecture