When you saute, use a flat bottom pan, minimum fat, high heat, and usually turn the food only once. When you stir fry, use a conical pan (wok), a bit of fat, and keep the food constantly moving to the bottom where the heat is.
The wok was developed to use a small, intense heat source, usually dried animal feces. Saute cooking was developed for a constant heat source, using a larger heat source. Then there's the thing about a French Chef ever using dried crap for anything in his/her kitchen.