This term is used in many ways. Just look around and you will find these: 

Sustainability is:

·     The word “sustainability” is derived from the Latin word sustinere.

·     Sustainable forest management has to keep the balance between three main pillars: ecological, economic and socio-cultural.

·     Managing resources: such that our quality of life can be shared by future generations

·     Sustainable investing: in companies that seek to combat climate change, environmental destruction, while promoting corporate responsibility.

·     A three-pillar conception of (social, economic and environmental)

Defined for the law of sustainability 

These multiple ways of using the term sustainability Goerner, Ulanowicz and Lietaer distilled down to this precise definition: “Sustainability is a network‘s capacity to sustain flow of energy, matter and information”

A new frame of mind 

This definition is a major breakthrough, a new frame of mind. It applies to all kinds of systems – forests, resources, investment, monetary systems, and it identifies one single indicator of performance: flow. 

A sustainable system enjoys unconstrained flow of energy, matter and information. Out of balance it will not be sustainable. Just that. 

Example: Sustainability of a country health care system

A country’s health care system is sustainable if it can cope with each case of a Corona patient, rapidly and effectively. If however this flow is hindered or constrained it is not sustainable.