Firewood

Firewood is any wooden material that can be used for fuel. The term usually refers to wood fuel that is not industrially processed, such as wood pellets, and instead takes the form of a recognizable log or branch. Firewood can be heat-treated and seasoned (dry) or unseasoned (fresh/wet). Two classes of firewood exist, which are either hardwood or softwood, depending on the species of tree that was cut. Firewood is a renewable resource, although demand for this fuel can quickly outpace its ability to regenerate on a local or regional level. Good forestry practices and efficiency advances in devices that burn firewood can improve local wood supplies. Smoke from burning wood can cause respiratory issues and other diseases. Transporting firewood long distances can also spread plant pests, diseases, and invasive species.