A concave mirror is a curved mirror that bulges inward, resembling a portion of a sphere. It reflects light inward to a focal point, making it useful in various applications. Common uses include in telescopes, shaving mirrors, and headlights, where it helps to focus light or magnify images. When parallel rays of light hit a concave mirror, they converge at the focal point, which is located in front of the mirror. This property allows for the creation of magnified images, making concave mirrors ideal for personal grooming and scientific instruments like telescopes.