How does a matchstick light up by using a magnifying glass ?

Light emitted by the sun is made up of photons, tiny packets of electromagnetic energy. Photons behave both as particles and waves. This quality is important because the nature of photons means that they are refracted when they pass through different media. The lens of a magnifying glass is curved to refract light particles in such a way that the eye perceives a larger image. A magnifying glass causes rays of light to change angle as they pass through the lens and meet at a specific point, focusing the energy of the photons. A combustible material, when exposed to heat and a source of oxygen, produces fire. Holding a magnifying glass so that the rays of light passing through the lens meet on a dry, flammable item, such as a piece of paper, concentrates the energy of the photons in a single spot and produces greater heat than the heat we feel on our skin from the sun. http://www.ehow.com/about_5256784_magnifying-glass-make-fire.html