ERD Symbols:
Entity relationship diagrams rely on three main symbols, as well as connecting lines. Rectangles are meant to signify an entity, which is a business object, role, concept, or person. Diamonds represent how entities share information. Similarly, connecting lines show the relationships between entities. Finally, circles signify attributes of an entity, or characteristics of an entity. These symbols are similar to that of a swimlane, although they have different meanings. In a swimlane, a rectangle represents an action, a circle the start and end of a process, and a diamond a decision. It can be difficult to keep these similar shapes straight!
Hello Julia,
The image you included in your post was very helpful in understanding the main symbols and their meaning in relation to ERDs. In the example diagram, the rectangle to the left states “entity”, which is very helpful in remembering that, then if there is a rectangle within the diagram, it always represents a specific entity. Also within the diagram you presented, the cardinality between the relationship and entities is present. The cardinalities that are present within this diagram are just a one-to-many relationship.