Hookah / Sheesha assembled
There are four fundamental parts of a hookah:
1. the base or smoke chamber, which is partially filled with water
2. the bowl, which contains the tobacco (or whatever else is being smoked); the heating apparatus is placed on top
3. the pipe, which connects the bowl to the base by a tube that plunges into the water
4. the hose, which connects to a second tube in the pipe that does not plunge into the water, but only the air of the smoke chamber
These basic parts do not vary in function; naturally, there are any number of decorations or subtle variations in form. The heating apparatus is usually charcoal, but in Saudi Arabia and the Persian Gulf, electric heaters are common. The charcoal is usually placed on a metal mesh or perforated aluminium foil, but these are often omitted to produce a more dense smoke. The hose may or may not be detachable — simple hookahs simply have a tube into the air of the smoke chamber; elaborate hookahs have three or more hoses in a single chamber, with filters attached at one or both ends of the hose.
Traditionally, hookahs have been ornately decorated. Some more modern hookah designs bear little resemblance to their ancestors. In general, traditional and modern hookahs have a very distinctive appearance and bear similarities to the ritually-used American Indian peace pipe.
When a smoker inhales through the tube, a pressure difference forces air past the coal, heating the tobacco, which gives off smoke; the smoke is pulled away from the tobacco, through the water, and into the air of the smoke chamber — whence it is inhaled by the smoker. Passing through the water partially filters tar and nicotine from the tobacco smoke, in addition to cooling it.