Depreciation is an accounting measure that records the loss in value of an asset as a result of usage, the passage of time, or obsolescence. Depreciation is applied only to tangible assets, such as property and machinery. It can also refer to the loss in value of a currency on the foreign exchange market. Depreciation in this sense contrasts with devaluation, which is an administered downward adjustment by a monetary authority in a currency's exchange rate.

See also: Amortization, Depletion