Smoking is essentially grilling and can be done on charcoal or gas grills. However, if you're all about the smoke, then you may consider buying a smoker.
There are two basic types of smokers: vertical water smokers and horizontal dry or pit smokers.
Horizontal smokers cook food by indirect grilling. These smokers have two chambers: one large one where food is placed, and a smaller offset fire chamber where the fuel source heats the food chamber indirectly.