The bright light of an LED flashlight can be an invaluable tool when on a camping or hunting trip, and a potential life saver in a home or car emergency. The power and efficiency of these light sources has made them incredibly popular throughout the world. How did these bright lights become so popular? How does the LED bulb in the flashlight actually work? Science and practicality have come together to create these innovative light sources - it may just be a good idea to know why.