List out the difference between a point source and an extended source of light.

Explanation

`{:("Point source of light "," Extended source of light"),("It is a point size source"," It has dimensions "),("It casts only umbra on the screen for an opaque object"," It casts both umbra and penumbra for an opaque object"),("Examples :Light emitting from a pin hole aperture "," Examples : A burning candle, a glowing tube light"):}`