What's the difference between a gasifier stove and a rocket stove?

A gasifier (like the Solo Stove Lite or BioLite CampStove 2+) uses a double-wall design to preheat secondary air, burning off smoke for a cleaner, hotter flame from small sticks. A rocket stove uses an L- or J-shaped combustion chamber and chimney effect to concentrate heat under a pot. Gasifiers tend to be cleaner-burning; rocket stoves typically handle larger fuel and put out more cooking power.