A cornice is a decorative architectural feature that typically runs along the top edge of a wall or building. It can be made from various materials, including wood, plaster, or stone, and serves both aesthetic and functional purposes. Cornices help to direct rainwater away from the building's walls, preventing water damage. In addition to their practical use, cornices add visual interest to structures by creating a transition between the wall and the roof. They are often found in classical architecture, such as in Greek and Roman buildings, and can also be seen in modern designs, enhancing the overall appearance of homes and commercial properties.