Even though both terms are often used synonymously, there is a difference in content between sustainability and sustainable development. While sustainability describes a static and constant state, the phrase sustainable development implies movement and dynamism. Rather, it denotes something emerging and becoming. (1)
A widely used definition of sustainable development dates from 1987 and comes from the Brundtland Commission, an independent UN expert commission on sustainable development. It states:

“Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their needs.”(2)