Instead of lighting your herb on fire to smoke it (combustion) vaporization uses an electric oven to bake your flower to a specific temp at which the cannabanoids release as smoke while the flower slowly bakes (vaporization). The resulting smoke is a lot cleaner on your lungs and you can get a lot more out of it. .2 g is 10 minutes of smoke in a vaporizer while 10 seconds of smoke in a bowl

The resulting vaporized herb is also a useful byproduct. Its effectively poorly decarbolized flower that you can use to make cannabutter with.