Subject: diffraction of light in terms of its electromagnetic nature

I have looked thru the archives and some of the answered questions like 
http://www.madsci.org/posts/archives/1998-12/913059266.Ph.r.html
http://www.madsci.org/posts/archives/2004-07/1091072493.As.r.html. But none of 
these answer my question which I'm going to write down again at the bottom. 
Actually I'm not able to fully clarify my question here because of restriction 
of words and if you check it throughly then you will find that there is 
no article on your website which explains diffraction in very nice and technical
way.

Question:
For the last 2 years I have read many physics books and webpages for 
diffraction of light but I never found any convincing explanation. It is really 
very easy to picturize the diffraction of waves which need some medium to 
spread like sound and water waves. But light is electromagnetic wave which 
doesn't need any medium. Diffraction is spreading of energy so that means when 
light diffract its electromagnetic energy spread over larger space but why and 
how does this spreading of energy take place? I don't need any explanation in 
mathematical form because I'm interested in physical understanding of 
diffraction of light first. If anybody really have the understanding of 
diffraction of light then email me, I can clarify my question further.

Re: diffraction of light in terms of its electromagnetic nature