Question

what is the real image send by the substance

Answer 1

An image which can be obtained on a screen is called real image and the image which cannot be obtained on a screen is called virtual image.

In case of mirrors, if the image is formed at the same side of the object, it is called real image. And, if the image is formed at the polished end (behind the mirror), it is called virtual image.

In case of lenses, image formed at the other end of object is called real, and image formed at same side is called virtual image.