I'm drawing an ER diagram for an ecommerce site that I'm building, and noticed something: the diamond that I am drawing between two models (or entities), which I understand is meant to symbolize the relationship between the entities, seems irrelevant.
The diagram could be drawn without the diamonds, and it would still show everything that I am conveying if I just connected entities with -|---|0- and similar connectors, without a diamond in between.
So what are the diamonds for?
