A graphical representation of the entities and the relationships between them. Entity relationship diagrams are a useful medium to achieve a common understanding of data among users and application developers.
In data modeling, an entity-relationship model (ERM) is a representation of structured data; entity-relationship modeling is the process of generating these models. The end-product of the modeling process is an entity-relationship diagram (ERD), a type of Conceptual Data Model or Semantic Data Model.
