Collecting and/or buying firewood consumes large amounts of time and income in developing countries. Indoor pollution is a health concern with traditional fireplaces.
Firewood is any wooden material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form, compared to other forms of wood fuel like pellets or chips. Firewood can be seasoned (dry) or unseasoned (fresh/wet). It can be classed as hardwood or softwood. Firewood is a renewable resource. However, demand for this fuel can outpace its ability to regenerate on local and regional level. Good forestry practices and improvements in devices that use firewood can improve the local wood supplies.
Source: Wikipedia - Firewood