A transaction is a business event that results in a measurable change in an organization's financial position. Transactions can include the exchange of goods or services for money, the purchase or sale of assets, the incurrence of liabilities, or the transfer of ownership of assets. In accounting, transactions are recorded in a systematic and consistent manner, using double-entry accounting, which means that for every transaction, at least two accounts are affected, with a corresponding debit entry in one account and a credit entry in another. The process of recording transactions is called bookkeeping.