Accountancy is the census and the economic measurement of the activity and the inheritance of an economic entity (undertaken, community, association, State, etc). The accountant is charged chronologically to record in documents known as "countable" the financial transactions of an entity (association, company, other company, morals or even individual).

Generally the behaviour of an accountancy results from legal, social or tax obligations. There are several types: Two have strong legal implications (determination of the benefit and thus of the taxes, information of the leaders, owners and lenders current and potential, etc.) they obligatory and strongly are regulated and controlled.

The public accounts determine the receipts and national expenditure and other public bodies; the general ledger whose essential objective is the information of the thirds is obligatory for the commercial company and all organizations. Two others are tools of decision-making aid for the policy of a country or company. For the latter it is without any obligation, but in practice essential even if its production process is complex. the national accounting gives an indication of the economy of the country accountancies of management, such as the cost accounting which measures the costs and the margins by centers and functions.

The partly double technique accountancy, used today in the comptabilté general one appeared in Italy before 1495. The monk Luca Pacioli (1445 - 1517) known under the name of FRA Luca dal Borgo, popularized the technique by publishing in Venice his treaty on accountancy.