The biggest difference between Halogen and LED lights is how they function. LED lights produce their light with an electrical current that is run in an arc pattern between two electrodes. Halogen lights produce light by heating up a tungsten filament.
As far as lifespan, LED lights last much longer than their traditional halogen counterparts. Typically halogen lighting lasts from anywhere between 2,000 to 6,000 hours, which is two to three times as long as an incandescent light. To put that into perspective, LED lights can last upwards of 100 times as long as an incandescent light bulb.
LED lights are also considered to be much more efficient than Halogen lights. The reason for this is that the light that is emitted by LED lights is produced using small amounts of power. Halogen lights are just slightly modified incandescent bulbs and use a great deal of energy.
Halogen light bulbs do cost much less than LED light bulbs which seems to be the main advantage of halogen lights. LED lights have a high production cost which contributes to the costly prices. However because LED lights last much longer, overtime they are a much more cost effective option for a number of different uses including fountain lighting, light strips, and even accent lighting.