Answer
1. A real image is formed when the rays of light after reflection or refraction actually meet at some point whereas a virtual image is formed when the rays of light after reflection or refraction appear to meet at a point. ... A real image can be formed in in a screen but a virtual image can be only seen in the mirror.
2. A convex lens or converging lens focuses the light rays to a specific point whereas a concave lens or diverging lens diverges the light rays. A lens is a transparent material (either curved or flat surface) based on the principles of refraction