Let A = {1, 2, 3, 4, 5, 6, 7, 8, 9}

and B = {2, 3, 5, 7}

Now, A AND B = A ∩ B = {2, 3, 5, 7}    [elements common in both sets A and B]

and A OR B = A U B = {1, 2, 3, 4, 5, 6, 7, 8, 9} [elements either in A or in B]