Question

What is the difference between convex and concave lens?

Answer 1

The nature of convex lens is converging
and that of the concave lens is diverging.
Convex lens forms both virtual and real images however concave lens can only produce virtual images.

Answer 2

Convex lens is thicker at the centre and tapers towards the edges while concave lens is thinner at the centre and thick towards the edges.
Convex lens are converging lens while concave lens are diverging lens.
The image formed by convex lens is real or inverted, virtual or erect,enlarged diminished or equal size of object whereas image formed by concave lens is always virtual,erect and diminished