The main advantage of wok beyond its constructed material is its curved concave shape. The shape produces a small, hot area at the bottom which allows some of the food to be seared by intense heat while using relatively little fuel.

The curve also provides a larger usable cooking surface versus western-styled pots and pans, which typically have vertical edges. This allows large pieces of food seared at the bottom of the wok to be pushed up the gently sloped sides to continue cooking at a slower rate. While this occurs another ingredient for the same dish needing high heat is being cooked at the bottom. The pointed bottom also allows even small amounts of oil to pool. As such large food items can be shallow fried, while finely chopped garlic, hot peppers, green onions, and ginger can be essentially deep-fried in both cases with very small amount of cooking oil. - wikipedia