Here is something that spells it out a little. Something to think about when your snapping shots.
Snapshots vs Photographs
Just to add a quick note to what is said in the article. Photographs invoke emotion or the feeling of being there. Snapshots do this but only for the person who was there. I find this to be the big difference. It is easy for me to find feeling in a picture I have taken, because it brings back the memory of being there at that moment, that is a snapshot. IF it were a photograph, it would bring the emotion or feeling of being there, to someone who never has been.