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

What is the Difference between Vitamin A, B, C, D, E, K and Other Vitamins

Vitamins are organic compounds in nature.  They are required by the body in very small amount but they are very vital too. Human body cannot produce them, so they must be present in diet. There are different types of vitamins, like A,B,C,D,E,K and many others.