Light Emitting Diodes (LED) are semiconductor devices that convert electrical current to light. The emitted light can be either visible or invisible, depending on the type of LED. When a voltage above the forward voltage drop of the LED (often around 2V) is applied in forward bias, current flows through the LED and it emits light. LEDs today are bright and can be used for indoor and outdoor lighting as well as indicators in circuit projects and devices. Current flowing through the LED must be limited using a resistor, to avoid permanent damage. When used for lighting, LEDs are far more efficient than incandescent bulbs for the same amount of light output. Consider using LEDs for your lighting projects, Scrolling message display, fancy shop signs, indicators etc.