So light travels faster than sound. Also you learned that sound cannot travel through a vacuum - it must travel through some matter. Through space light travels at a speed of 186,000 miles per second. When you turn on a light the room is flooded with light all at once. Every corner is lighted up at the same time.
Light can also travel through matter like air, glass, and water.
However, matter slows down the speed of light. When it slows down it changes direction or bends. This bending is called refraction. Another way we measure light is a unit called a candle. This measures the intensity of light.