LED (Light Emitting Diode). There are two types of LED lighting; Mains voltage and Low voltage, both of which operate on DC voltage via converters, either in the lamp itself or in the Driver.
Mains voltage LED lamps are simple and can be used to replace a conventional light source, when they both have the same lamp holder requirements. (The most popular change is using a GU10 LED in a GU10 fitting. Here you will be substituting LED for a Halogen light source, so the level of illumination will be much lower).
Low voltage LED lamps require a transformer (Driver). The transformer converts the 230 volts into either usually 12 or 24 volts DC. The number of lamps that can be used on a transformer is dependent on the total wattage of the lamps, which should be less than that of the total wattage capacity of the transformer.
LED lighting works by passing a current through a diode element. Where a conventional lamp heats up a filament, which then glows, an LED gives off light when current flows through it, with almost no heat generated. An LED runs cool and is great where heat is an issue.