Huygens principle states that
1) Every point on a given wavefront may be considered as a source of secondary wavelets which spread out with the speed of light in that medium. 2) The new wavefront is the forward envelope of secondary wavelet at that instant.
What does this actually mean in both theoretical and practical view? Does this explain in this way: Taking sun as a source, As the light from sun reaches every object, Do each & every object actually act as a new source of that light"..? Or a ray of light inside a room causes its walls to reflect the light. Then, do the walls act as a new source?
Explanation and examples related to both principles would be helpful...