Types of smoker.
There are many types of smoker for cold or hot smoking or both.
As stated in an earlier post you can smoke food in almost anything.
A gas BBQ with a hooded lid is maybe the easiest and cheapest if you already have one.
Then you have the kettle type BBQ. The best known is probably Weber brand. There is very little you cannot do with a kettle BBQ. Very versatile.I have 2. One came with a gas burner which I have never used. Real bbqs are stick burners.
Then there are cabinet smokers. These can be very basic. Just a metal box with a heat and smoke source. They can use gas, wood or heat beads for heat and smoke.
They can be very complex. All the way up to computer controlled with small fans which switch on and off to adjust temperature. They can show a graph of all the temp rises and falls. Have 'biscuit' type wood discs that get fed in automatically as needed.
Then there are the 'offset smokers'. Two barrels joined together. The small barrel has the fire and the larger one holds the food. This is to allow better temperature control. These are very popular in the U.S of A. They come in all sizes from standard back yard BBQ to small fuel truck sized monsters.
Of course being American they can be very elaborate with multiple cooking areas, hot running water and outrageous designs.
There are also devices that burn sawdust or wood chips to be added to any type of smoker. A popular type is the A-maze-smoker. Pic below.
Also for those who like to tinker in the shed there are as many types of smoker as there are sluices and high bankers. Commonly called UDS or Ugly Drum Smoker. The T shaped on in the pic below is pretty popular.
Only restricted by your imagination.
Then there is the cold smoker. It can be used in any of the above types of smoker or to cold smoke foods in any container from a cardboard box to plastic crates etc etc.
If you a keen to get into smoking then do the usual research. YouTube is great.
The Aussie BBQ forum is also a great resource.
http://www.aussiebbq.info/forum/index.php?sid=878a390eb35a4bb5e6e79c68fdc0ffe8
Got a leg of lamb in the weber as we speak
Below are pictures of various smokers.
Cabinet smoker.
Cold smoker
UDS (ugly drum smoker)
The A-maze-n smoker
Offset smokers. Yes the motorbike is a smoker.