There have been very few developments in lighting technology since the lightbulb was invented over a hundred years ago. The only major development to list is the invention of LEDs. This stands for Light Emitting Diode. These are a wonderful technology created through superconducting materials. They have a lot of wonderful applications. How does this actually work your asking? LEDs consist of semi conducting materials and work very much like other types of diode. A current flows from one side to the other in one direction until it reaches a small hole. The energy is then converted into a photon which is a particle of light. This hole in the LED is called a band gap. The size of the band gap is the major determining factor in what each LED is capable of. The size of the hole is what changes the wavelength of the diode. Technology around the band gap has really gotten better since we started using better materials. There are a lot of different advantages that are offered by LEDs that an incandescent light bulb simply can’t do. One of the primary ones is that LEDs are so much more efficient. This causes flashlights made with LEDs to have much better battery life and to not get nearly as hot. Incandescent light bulbs lose most of the energy put into them to producing heat. LEDs can last a really long time because they use a low amount of current and don’t produce any heat. Some studies have shown that LEDs can last as much as one hundred thousand hours. Some of the LEDs made in the early 1970s are actually still glowing bright today. If you are looking for an emergency flashlight your best bet would probably be an LED flashlight. They are significantly brighter than incandescent based flashlights which makes them much better for signaling people at a distance. LEDs are commonly used for a lot of different things. I think one of their coolest applications is in party lights as big gathering. They can produce brilliant effects at night because of the wide array of colors they can produce. When it comes down to it though, when you need a flashlight an LED flashlight is your best bet. They have a much better illuminating distance and produce a much clearer white light. If you are only going to have one flashlight in your home the absolute best thing you can have is a high quality LED flashlight. John Dallinger has worked as a proffesional in the electronics industry for more than two decades. For more of his recent work please see How LEDs Work [1] and Gold Diamond Necklaces For Women [2] [1] http://ezinearticles.com/?How-LEDs-Work&id=3864659 [2] http://www.infobarrel.com/Diamond_Necklaces