The magnification produced by a plance mirror is +1. What does this mean ?

Explanation

Magnification produced by a mirror is given by the relation:
magnification (m) = `("height of the image (h.)")/("height of the object (h)")`
The magnification produced by a plane mirror is +1, which means that the image formed by the plane mirror is of the same size as that of the object. The positive sign shows that the image formed is virtual and erect.