This Day in History: Sustainability Defined
On December 11th, 1987, the Brundtland Commission defined sustainability. The report, Our Common Future, defines sustainable development as:development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It contains within it two key concepts:
Feeling froggy? Read the full text from the UN.
Sustainable development has a lot of categories. For a full list I recommend the all knowing Wikipedia.
Although biased, I really think how we handle waste is a major component of sustainability. Here is some info on sustainability