Exercise - Variety with a low sun

I know about the three main lighting, frontal lighting, side lighting and back lighting but I have very little knowledge of what the edge lighting is.
As far as the definition in the workbook is concerned,
Edge lighting is when the sun is outside the viewfinder frame and the edge of the sun is lit. shooting is done toward the sun.
It still isn't very clearn so I googled and found:

http://blog.corporatefineart.com/2009/04/edge-lighting.html
" Rim light (or edge lighting) helps to separate the subject from the background in a very artistic way, and it helps to give dimension to a picture. No matter what subject you might be shooting, lighting along the edge can dramatize an image and make it very appealing."
I am not 100%sure but I think this is edge lighting according to the definition above.


Edge Lighting: Where the subject is lit at the edge


Side lighting: The sun to the right of the camera


back lighting: This photo was shot toward the sun with it being lit behind the subject.


frontal lighting: with the sun behind the camera striking the subject fully



By the time I finished doing this assignment, my head was hurt and my eyes were sore because I had to look where the sun was and many times I had to look directly into the sun.
Eventhough I like the photos taken but I did not enjoy hurting my eyes so much!!