The image formed by reflection in a plane mirror is described as a virtual image.
The image formed by the light that passes through a converging lens is a real image.
The term 'virtual image' is used to describe an image formed by rays of light that do not pass through the image – dashed lines in the top diagram. In the second diagram, the rays do actuall pass through the image.
Real images cannot be formed by plane or convex mirrors – they only form virtual images. Real images can be formed by concave mirrors or by concave or convex lenses. If you look into the concave surface of a spoon, you will see a real image. Turn it over for the convex surface and the image will be virtual.
