Firewood is any wood material that is collected and used for fuel. In general, firewood is not highly processed and is in the form of a kind of recognizable log or branch compared to other forms of wood fuel such as pellets or sawdust. Firewood can be seasoned (dry) or unseasoned (fresh/wet). It is generally classified as hardwood or softwood.

Firewood is a renewable resource. However, the demand for this fuel may outpace its ability to regenerate at the local or regional level. Good forestry practices and improvements to appliances that use firewood can improve local wood resources.

Transporting firewood over long distances can potentially carry diseases and invasive species.

Harvesting or collecting firewood varies by region and culture. In some places there are special areas for collecting firewood. Other locations may integrate firewood harvesting into a plot preparation cycle to grow food as part of a field rotation process. Collection can be a group, family or individual activity. Tools and methods for harvesting firewood are diverse.

Australia
In Australia, firewood is typically harvested from either eucalyptus trees or pine trees (both grown in large quantities). Dead branches left in the ground often attract termites, thereby reducing rot and causing rot.

North America
Some firewood is harvested in "woodsheds" managed for this purpose, [2] but in densely wooded areas it is more harvested as a by-product of native forests. Preferred is Deadfall, which hasn't started to rot yet, as it's already partially seasoned. Standing dead lumber is considered better because it contains less moist organic material in its trunk, which allows tools to stay sharp longer, as well as being both aged and less rotten. Harvesting this form of timber reduces the speed and intensity of wildfires, but it also reduces the habitat of nesting animals such as owls, bats and some rodents.

Timber harvesting for firewood is normally done manually with chainsaws. Thus, longer parts – requiring less manual labor and less chainsaw fuel – are cheaper and limited only by the size of the furnace box. In most of the United States, the standard measure of firewood is a cord, or 128 cubic feet (3.6 m), although firewood can also be sold by weight. The heating value can affect the price. Prices also vary considerably based on the distance of the wood and the quality of the wood.

Buying and burning cut firewood just a short distance from the final destination prevents the accidental spread of invasive tree-killing insects and diseases. [