A displacement map is a technique used in computer graphics to create detailed textures on 3D models. It works by altering the surface of a model based on the brightness values of a grayscale image. Lighter areas of the image push the surface outward, while darker areas pull it inward, resulting in a more complex and realistic appearance. This method is commonly used in various applications, including video games and animation, to enhance visual detail without significantly increasing the model's polygon count. By using a displacement map, artists can achieve intricate designs, such as terrain features or fabric textures, efficiently.