The concept of depreciation of fixed assets is very controversial. Three approaches have been adopted by the doctrine to specify its nature and purpose. These are the legal-accounting approach, the economic approach and the financial approach.For the legal-accounting approach: the notion of depreciation is linked to the depreciation of fixed assets. In this context, the chart of accounts defines it as "the accounting recognition of a reduction in the value of an asset resulting from use, time, changes in technology and any other cause".For the economic conception: depreciation is a procedure allowing to distribute an investment cost between the financial years during which the fixed asset which is subject to depreciation is effectively used by the company. The emphasis here is not on the value of the asset in the balance sheet, but on the operating expense that must be incurred in each of the years in which the asset is used.