What is edge modeling?

I’ve heard of box modeling and sculpting but I haven’t found alot of descriptions or examples of edge modeling. If anyone can tell me what it is, I would greatly appreciate it especially if it can be used to model objects based on reference images.

http://cgcookie.com/blender/series/modeling-a-human-head/

Thanks for the examples!

This thread is solved. Please delete

Threads do not get deleted so it may help other members in the future who may have the same question and who should use the forum search function.