The generation and safe distribution of electricity is one of the most important human technological developments; without it, the world – what you could see of it – would be a vastly different place. The ability to light spaces that would otherwise be unlit owing to a lack of natural light from the sun has rendered everything in the pre-industrial world, from manufacturing to communication to basic creature comforts, practically obsolete.

Today, rather than face the problem of not having artificial light sources, you may be confronting the less urgent but still important issue of what kind of light you prefer to illuminate your surroundings. For a number of reasons, much of the globe has moved from traditional halogen lighting systems to light-emitting diode (LED) bulbs.

Halogen lights are a kind of incandescent light, meaning that the proximate source of the light is heat. Fires and stars are included in this category, but obviously retailers are unable to offer them alongside incandescent light bulbs. Halogen bulbs are an "elite" type of incandescent bulb, offering up to three times the life span compared to their predecessors.

Halogen lamps, also known more descriptively as tungsten-halogen, quartz-halogen or quartz-iodine lamps, contain filaments (thin strands) of the element tungsten (W on the periodic table of elements) sealed in an enclosed space along with small amounts of gases that do not react with other elements and are thus not consumed in chemical processes inside the bulb.

Halogen lamps are bright, compact and inexpensive, all of which are enormously advantageous. However, they are also very hot and – as you've probably experienced – can burn skin; they also emit ultraviolet and infrared radiation that can damage certain materials.

LED lights leverage the power of semiconductors to use electrons in atoms to generate photons, which can be thought of as massless "packets" of light. The central component in this scheme is the p-n junction diode, and the result is not incandescence but electroluminescence.

These light sources, found in car headlights as well as decorative, grow and housing lights, are more energy-efficient than halogen lights and also emit far less heat and harmful UV and IR radiation. They also offer a wider range of colors, are more compact and last longer.

Getting LED replacement bulbs for halogen lights usually is not difficult, especially in the case of higher-wattage – and hence brighter and hotter – bulbs, such as 230 watts (W). (Watts are the standard unit of power, electrical or otherwise, in physics.) You just choose the kind you want and make sure the socket is the correct size, just as you would if replacing an old halogen bulb with a new one.

In the case of replacing lower-wattage bulbs (say, 12 W), the situation may be more complicated. The housing of these lights contain transformers that halogen lights are manufactured to work with. As LED lighting becomes more popular, more of these lights come equipped with circuits that allow for automatic integration into your existing system. In other words, the light fixture might be made specifically for halogen lights and not LED bulbs, so trying to insert an LED bulb wouldn't work.

If you cannot find such bulbs for your particular light fixture, you will have to have the housing of the light itself fitted with a device called an LED driver. For this, you should enlist the services of a professional electrician.