Consumption is the using up of a resource. Discussions of human consumption of resources plays an important role in both economics and environmentalism. In Keynesian economics, "consumption" is short-hand for personal consumption expenditure and is determined by the consumption function, especially by the marginal propensity to consume. It is part of aggregate demand or effective demand.
Consumption can also be defined as "the selection, adoption, use, disposal and recycling of goods and services", as opposed tho their design, production and marketing.