The silvered-glass mirrors found worldwide today started in Germany almost 200 years ago. In 1835, German chemist Justus von Liebig developed a process for applying a thin layer of metallic silver to one side of a pane of clear glass.
We have three basic kinds of mirror as explained below.
Plane Mirrors
A plane mirror has a flat or planar reflective surface. Light rays striking a plane mirror, proceed at an angle of reflection that equals the angle of incidence. Said plane mirror creates an image of spatial objects located directly in-front of itself, and these images appear to be behind the plane in which the mirror lies.
The image formed by a plane mirror is virtual (light rays do not actually come from the image), and thus, it is not, or cannot form, a real image on a screen. The reflected image is upright, and of the same apparent shape and size as the object it is reflecting (if object and image are observed from an identical apparent/ real distance of depth).
Plane mirrors are the only type of mirror for which an object produces an image that is virtual, erect, and of the same size as the object, and in all cases irrespective of the shape, size, and distance from mirror of the object. Note that the same geometrical/ visual effect is possible for other types of mirror (concave and convex) but only for particular arrangement(s) of object/image position.
Curved Mirrors
A curved mirror is a mirror with a curved shaped reflecting surface. The surface may be either convex (bulging outward) or concave (recessed inward). Most curved mirrors have surfaces that are shaped like a segment of a sphere, but other shapes are sometimes used in optical devices.
The most common non-spherical type are parabolic reflectors, employed in optical devices such as reflecting telescopes. Also image-distorting curved mirrors are sometimes used for entertainment. They have convex and concave regions that produce deliberately distorted images. They also provide highly magnified or highly diminished (smaller) images when the object is placed at certain distances, which we can name as anamorphic, inconsistent, or varying perspectives.
Convex and Perspective Mirrors
The use of convex mirror began in Flemish painting practice of the fifteenth century when it became fashionable to depict scenes reflected in convex spherical mirrors.
A convex mirror or diverging mirror is a curved mirror in which the reflective surface bulges towards the light source. Convex mirrors reflect light outwards, therefore they cannot focus light. Such mirrors always form virtual images, which cannot be projected on a screen, because the image is located ‘inside’ the mirror. The image is smaller than the object, but gets larger as the object approaches the mirror.
Sometimes a flat, or in particular a concave mirror is known as a perspective mirror, because it allows an onlooker to see a relatively stable, or unchanging vista from various viewing angles or viewing locations; whereby the image size and shape are relatively fixed and the observer can readily observe a spatial scene.
Concave Mirrors
Concave mirrors have been known since antiquity, and, in the intervening centuries they have sometimes been named burning mirrors because they tend to focus sunlight and set objects on fire! A concave mirror has a reflecting surface recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. Unlike convex mirrors, concave mirrors show widely varying image shapes/sizes depending on the distance between the object and the mirror.
Concave mirrors can provide a magnified image of the face for applying make-up or shaving (object closer than centre-of-curvature). Concave mirrors can also provide demagnified images (object further than centre-of-curvature), for example in the landing system of aircraft carriers.
In illumination applications, concave mirrors are used to gather light from a small source and direct it outward in a beam in torches, headlamps, and spotlights, or to collect light from a large area and focus it onto a small spot, as in concentrated solar power.
Perspective Research Centre 
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