The vigil lamp is usually placed before an icon as a reminder that Jesus Christ is the light of the world and illumines our souls. There are two basic types of vigil lamps: hanging and standing. Usually vigil lamps are lit using oil, usually olive oil, as the fuel feeding a floating wick. The vessel holding the oil is a cup usually made of heat treated glass. Sometime lamps that burn a wax, usually bee's wax, candles are used. In Orthodox Christian usage, electric lamps are not used.