Forward phase dimming (also called TRIAC or leading edge) cuts the leading edge of the AC sine wave. It was originally designed for incandescent and magnetic low-voltage loads, is inexpensive, and works with many LED drivers labeled 'TRIAC dimmable.' However, it can cause buzzing, flicker and has a higher minimum load. Reverse phase dimming (also called ELV or trailing edge) cuts the trailing edge of the sine wave. It was designed for electronic low-voltage transformers and works better with most LED drivers, offering smoother dimming, lower minimum load, and less buzzing. Reverse phase dimmers are generally more expensive. When selecting a dimmer, always check which type your LED driver requires — using the wrong type can cause poor performance or damage. Many modern dimmers are 'universal' and support both modes.