The lighting of lamps(diya, in Hindi), is an oil lamp usually made from clay, with a cotton wick dipped in ghee or vegetable oils,that forms a part of celebrations and rituals of the festival. Houses are decorated with small diyas placed at boundaries and entrances. In fact, the name of Diwali is derived from the Sanskrit word Deepavali, which means the row of lights (“deep” means Diya and “avali” means row).[Source: Wikipedia]