Highlighting Relationships in Entity-Relationship Diagrams
The ERD tool provides many useful features to help you work with diagrams. One of them is the highlighting of the context parts in the diagram.
You do not need to guess which relationship connects which entity attributes. Just click on a relationship to select it and the context highlighting shows you which attributes it connects.
In the same way, if you click on a key attribute (primary or foreign), the associated relationship will be highlighted.
The highlighting is a small helper but it will make your navigation in entity-relationship diagrams much easier.
Relationship highlighting in entity-relationship diagrams (ERD tool)