You do have to differentiate between hot-smokers and cold-smokers.

Hot smokers are a way of smoke-flavouring food whilst cooking it. They are small and usually in one piece.

Cold-smokers are a way of preserving and drying food in smoke. The smoke usually comes from a firebox through a tube into the smokehouse.

Slightly different techniques ars needed, because cold-smoked food is usually as dry as possible before smoking, often salted for a while to dry it out.

I only hot-smoke, but people here who have access to large quantities of fish, for instance, usually cold-smoke. There are people who make a living from cold-smoking.