There are two main types of dimming that can be used with LED light sources. These are TRIAC (Triode for Alternating Current) dimming and 0-10 Volt dimming.
TRIAC dimming relies on adjustable timing of power at the start of each AC half cycle, which alters the voltage waveform to dim a light source. TRIAC dimming is almost instantaneous and wastes very little power.
0-10 V dimming utilizes a DC voltage that varies from 0 V to 10 V to dim a light source. 0-10 V dimming typically runs at a low current with little voltage drop.