Entity Relationship Diagrams
Entity Relationship Diagrams (ERM) are used to model the information within a relational database. These diagrams can help enforce the Normalisation process. Once ERMs have been designed they can be used to create tables within the database.
Diagram 5.1 shows supporters have a one to many relationships with Activities, Supporter Letters, and Donations. The fork end of the blue line in diagram 5.1 represents a many side of the relationship.