Well, the reason why is just this....There are so many cartons of eggs sitting on supermarket shelves with so many different name types that it's completely confusing as to what they really are! So following are the different types of eggs, followed by links to other articles and videos about eggs and egg production in the USA that will define the types of eggs and what they REALLY ARE. You will find the information enlightening.
PASTURE RAISED EGGS
ANIMAL WELFARE APPROVED
UNITED EGG PRODUCER CERTIFIED
The following websites contain information about eggs and their production in the USA: