You Say Street Art, I Say Graffiti. Let's Discuss.

Here is an article from the San Francisco Chronicle discussing the finer points of street art vs graffiti. As for me, I see little difference - unless you want to get nit picky. In my mind, graffiti is essentially spray paint while street art uses wheatpaste, stensil and stickers. However I think an argument can be made that says that graffiti is anything applied illegally or surreptitously in the environment while street art might be, like a commissioned wall mural, just another pices of art on the street. Read the article and decide.