A downlight is a light that has been recessed into a ceiling that throws light downwards in a narrow beam.
Downlights and energy efficiency
Using downlights rather than pendant or fluorescent fittings will mean you need to install more lights to light the same area, resulting in higher energy use and running costs. In the past, downlights often used halogen lamps which are high energy users. Low-energy downlight fittings are more commonly used now, including LEDs (light emitting diodes) or CFLs (compact fluorescent lamps). Both are more efficient and cheaper to run than halogen downlights.