A channel letter sign is a custom-made sign composed of individual letters or shapes that are cut out from metal (aluminum) and mounted on a raceway or backer (frame). These letters have a depth dimension, creating a three dimensional appearance, they are often illuminated, either from the front or back, using LED lights, giving them a vibrant and eye-catching appearance, especially at night. 

Channel letter signs are popular for businesses, building facades, and storefronts, offering a professional and visually appealing way to display brand names and messages.