PDLC stands for Polymer Dispersed Liquid Crystal: liquid crystal in the form of microscopic droplets dispersed in a solid polymer. A thin layer of this material between two transparent, electrically conductive films forms a switchable film. Without voltage the film is frosted white and scatters light; with voltage it becomes clear. [1][8]
PDLC goes by many names: smart film, smart glass, switchable film, switchable glass, privacy glass, smart tint, LC glass, e-glass, magic glass or brand names such as PRIVA-LITE, LCG and Polyvision. The principle is always the same.
Good to know: PDLC mainly controls visibility, not the amount of light. Even in the frosted state plenty of daylight comes in. If you want to darken a room or block solar heat, also look at SPD or electrochromic glass, or combine PDLC with solar-control film.