Sustainability requires a way of life and working that does not overexploit, squander or even ruin the natural resources that form the basis of human life. The concept behind this term was already described hundreds of years ago in forestry. It means a form of exploitation where there is as much wood harvested as is grown during the same period of time. This ensures the wood will never be totally harvested, but will be able to regenerate and can be used by future generations as well.