A mirror is a specialized reflective surface designed to redirect incident electromagnetic radiation, most commonly visible light, based on the principle of specular reflection. This optical phenomenon mandates that the angle of incidence equals the angle of reflection, allowing the surface to produce a virtual, upright image. Mirrors can be manufactured using highly polished metallic coatings, or their geometry can be precisely curved into parabolic or spherical shapes. These engineered surfaces are fundamental components in various technological instruments, including telescopes and periscopes, where they are utilized to gather, collimate, and focus light waves for specific scientific or industrial applications.