What is the Difference Between Similar But Different Things, Terms, and Objects

What is the Difference between Scallops, Clams, Oysters and Mussels

Life is present in many different forms on this planet earth. Large animals, birds and insects are the most common forms of life. However, water bodies also hold a great verity of living creatures. Bivalve Mollusk is the family of invertebrates, which have great variations in size nd shape.