There are several lighting technologies that can be used to power a projector. UHP lamps are the closest thing to a standard lighting system for projectors, given their high brightness capability, but lamps only last a few thousand hours, and tend to degrade gradually over time, affecting the colour output.
LED lighting is gaining popularity within the projector market, especially in portable models, given how compact LEDs can be – note that, while LED models will last for much longer than UHP ones, though, brightness output tends to be comparatively lower.
Bigger spenders should consider the laser projectors in this guide, as they offer more vivid and consistent colour over a longer period of time (over 20,000 hours). The technology is more pricey, though is generally used in top-range, home cinema models.