Food smoking is the process of flavoring cooking or preserving food. Wood of Hickory, mesquite, oak, pecan, alder, maple and fruit trees such as Apple, Cherry and plum are commonly used for smoking meat and fish.
Hot smoking exposes the food to smoke and heat in a controlled environment. Foods that have been hot smoked such as Hams and hocks, sausages, chickens, pork ribs, beef jerky cheeses and fish are fully cooked once they have been properly smoked. Hot smoking occurs within a temperature range of between 165 degrees F to 215 degrees F. Within this range food is fully cooked, moist, succulent and flavorful.
If the smoker is allowed to get hotter the foods will shrink, buckle or even split. This is due to the moisture and fat being cooked away.

The Propane or Gas Smoker
This newer smoking technique was designed to smoke meat and fish in a more controlled environment. The smoker is like a large upright oven with 2, 4 or 6 racks and a sealed front door with air vents in the top to draw the smoke upwards. The heat is generated by lighting a gas burner from underneath the smoker on top of which is a steel or iron box that contains wood or charcoal or both to provide the smoke. The box has a few vent holes on the top only so by starving the heated wood of oxygen it will smoke and smolder instead of burning in a flame. This method uses less wood.

The Electric Smoker
This type of smoker is similar to the gas smokers but uses an electric hotplate to burn wood chips or bisquettes usually fed on some sort of conveyor belt to keep new chips or bisquettes going to the hotplate without heat lost by continual opening of the door.
With this system you load it up and leave it for 2, 4 or 6 hours depending on what you are smoking.

The Charcoal Smoker
This type of smoker is very similar to the gas and electric versions but uses charcoal to supply the heat and wood chips to supply the smoke.