Entity Relationship Diagram

Entity Relationship diagram or even E-R diagram in a nutshell, is a graphical representation with the overall logical structure of the database. The entity-relationship model will be based upon a perception of the real world that includes a collection of essential objects, called agencies, and of associations among these items. The set of all entities of identical type are classified an entity set, and the list of all relationships with the same type are termed as a relationship set.