Smoking is the process of curing, cooking, or seasoning food by exposing it for long periods of time to the smoke from a wood fire. "Hot smoking" is a several-hours-long process that can be used to fully cook raw meats or fish, while "cold smoking" is an hours- or days-long process that is generally used to preserve or flavour foods (usually meats or fish, but sometimes cheeses, vegetables, fruits, and even beer).
The fuel used for smoking may contain flavoring ingredients. For example, Chinese tea-smoking uses a mixture of uncooked rice, raw sugar, and tea, heated at the base of a wok, to slowly smoke and flavor meat and other foods. In Europe, the traditional wood burnt to smoke fish and meat is alder, but oak is more often used now, and beech to a lesser extent. In North America, hickory and mesquite wood, in addition to oak and alder, and also sometimes wood from fruit trees such as cherry and plum, are commonly used for smoking.
Historically, farms in the western world included a small building termed the smokehouse where meats could be smoked and stored. This was generally well-separated from other buildings both because of the fire danger and because of the smoke emanations.