Question 11 :
An entity is something that can be identified in the user's work environment; something that the users want to track.
Question 12 :
Entity instances are associated by relationship classes.
Question 13 :
1:1, 1:N and N:M relationships are also known as HAS-A relationships.
Question 14 :
In a 1:N relationship, the parent is the entity on the one side of the relationship and the child is the entity on the N side of the relationship.
Question 15 :
A maximum cardinality is the maximum number of entity instances that can participate in a relationship instance.