Traditionally used with oil and cotton wick lit as a lamp for meditation or bringing blessings into the home. Diyas are especially used during the festival of Diwali which is also known as The Festival of Lights. Lighting of the diya is considered essential because it signifies purity, goodness, good luck and power. The presence of light means the non-existence of darkness and evil forces. Each type of oil used in the diya is said to bring a different effect.