Self-sufficiency (also called self-containment) is the state of not requiring any aid, support, or interaction, for survival; it is therefore a type of personal or collective autonomy.  On a national scale, a totally self-sufficient economy that does not trade with the outside world is called an autarky.
The term self-sufficiency is usually applied to varieties of sustainable living in which nothing is consumed outside of what is produced by the self-sufficient individuals. Examples of attempts at self-sufficiency in North America include simple living, homesteading, off-the-grid, survivalism, DIY ethic and the back-to-the-land movement.
Practices that enable or aid self-sufficiency include autonomous building, permaculture, sustainable agriculture, and renewable energy. The term is also applied to limited forms of self-sufficiency, for example growing one's own food or becoming economically independent of state subsidies. The self-sufficiency of an electrical installation measures its degree of grid independence and is defined as the ratio between the amount of locally produced energy that is locally consumed (either directly or after storage) and the total consumption.