Cardinality describes the actual number of entities of the same type involved in a process. So in our class we have 30 students of the student entity type. The cardinality would then be described as 30 students. We can describe the number as 0, 1, many (and then can display the actual minimum and maximum allowed). We can also say whether the number is optional or mandatory. For instance, it is mandatory we have one instructor for our class. It is not optional.

What are at least three other examples of cardinality?