Wood has been used as a fuel for a very long time indeed. Wood burning stoves were invented in the 17th century, and are still in use today. However, burning natural wood in stoves and fireplaces has declined recently. There are other fuels that are generally considered to be cleaner and better.
Many of those who still use wood in their stove or furnace are able to gather their own firewood. Others, however, may be obliged to purchase it. Firewood is commonly sold at supermarkets, especially in rural areas. It is usually sold by the cord and is generally cut and the bark is removed. In some cases logs with the bark on may be sold for decorative purposes.
Firewood is a by-product of the timber industry, generally consisting of wood that is too small to be of use as lumber. It can also be produced by trimming of trees and other forest management techniques. Because of this it can come from a variety of trees. Hardwood such as oak or ash is the best firewood, as it burns well and produces more heat. Cedar and mesquite are more valuable as chips for smoking and BBQ. Softwoods such as pine, fir, and spruce are best used as kindling. In some rural areas firewood may be delivered.
It is essential that firewood be properly seasoned and dry. It is generally bundled and stored on racks. Most of the time it comes from small logs which are cut down and then split. Once dry, it is corded and stacked.
Wood is not as efficient a fuel as coal or gas. The heat from a wood fireplace is notorious for going out of the chimney rather than into the room. Many fireplaces are used for ambiance rather than heat.