When light falls on a surface, the direction of ray is changed. This Change in direction is known as reflection of light
Shadow is an image formed by obstruction is light.
Eg .: You see our reflection in a pool of water or mirror.
Eg .: If you place your hand in front of a candle, you will see the image of the hand on the wall. This image will show only the outline of the object placed in front of the light source.