Apollo and Demeter are two of the most important Olympian deities in Greek mythology. Apollo is the god of music, poetry, art, oracle, purification, plague, medicine, sun, light and knowledge, and is often recognized by the laurel wreath he wears. Demeter, on the other hand, is the goddess of the harvest and fertility, and presides over grains and the fertility of the earth. She is often depicted with a wheat sheaf or cornucopia, and is one of the most worshipped deities in ancient Greece.