Question

Explain the difference:

Point sources and extended sources of light.

Answer 1

Point Source of Light	Extended Source of light
It is that source of light that forms only the umbra region on the screen of the shadowed object.	It is that source of light that forms the umbra as well as the penumbra region on the screen of the shadowed object.
e.g., a pinhole through which sunlight is entering is a point source of light.	e.g., the sun is an extended source of light.