Final answer:
The crows feet notation on an ERD is a type of cardinality constraint used to represent the number of related entities in a relationship.
Step-by-step explanation:
The crows feet notation on an ERD is a type of cardinality constraint. It is used to represent the number of related entities in a relationship. In an ERD, the crows feet notation is depicted as small lines or hash marks on the line connecting the entities. The lines indicate the cardinality of the relationship, such as one-to-one, one-to-many, or many-to-many.