A good fuel is one which burns easily, produces a large amount of heat and does not leave any undesirable substance. 
For centuries, wood was used as domestic and industrial fuel. But now it has been replaced by fuels like LPG. In many rural parts, people still use wood as a fuel because of its easy availability and low cost. However, burning of wood gives a lot of smoke which is very harmful for human beings. It causes respiratory problem. Also calorific value of LPG (55000 KJ/Kg) is larger than the calorific value of wood (18000 KJ/Kg)