Gikfun 3mm LED Bulb Light Assorted Kit DIY LEDs for Arduino (Pack of 100pcs) EK8435

In the late 1800s, Thomas Edison invented the first commercially viable light bulb. Light bulbs like this work by passing large amounts of current through a thin filament, which is basically a wire. The filament gets so hot that it starts glowing, and emitting light. This process is very inefficient - less than 5% of the energy going into the bulb gets turned into light - the rest gets turned into heat. A much more efficient source of light is a light emitting diode, or LED. LEDs basically contain two specialized semiconductors that are stuck together, and when you apply a large enough voltage across them, they emit light from a process called electroluminescence. There is some heat produced, but overall the process is a lot more efficient, and you can get a lot of light from a very small device. On average, they last for over 10 years of continuous usage, so you can see why they are po