Ganesha is also one of the five Gods, the worship of whom was popularised by Adi Shankaracharya;
the other four are Vishnu, Shiva, Devi and Surya. The worship of these five deities is called the pancayatana puja.
The large head of an elephant symbolizes wisdom, understanding, and a discriminating intellect that one must possess to attain perfection in life.
The wide mouth represents the natural human desire to enjoy life in the world.
The large ears signify that a perfect person is the one who possesses a great capacity to listen to others and assimilate ideas.
The trunk relates to the power of human mind which must be strong enough to face the ups and downs of the external world and yet delicate enough to explore the subtle realms of the inner world.
Ashtadravya means eight things, which are Coconuts, Molasses, Sesame oil, Sugar cane, Lemon, Rice flakes and rice used in the Ganapathy Homam and is to appease Lord Ganesha and bless you with Wealth, Prosperity and Long Life.