The dual aspect concept that every accounting transaction has two sides.
Therefore the balance sheet should always remain in balance.
For example, if services are sold by a company for cash, the company's Sales figure increases AND its Cash increases.
Taking another example, if a company borrows money, its Cash increases AND its Liabilities (to repay the money in the future) also increase.
This system is sometimes known as 'double entry bookkeeping'.
An error resulting from the inappropriate duplication - or inappropriate repetition - of an entry (or part of an entry) in a financial information system or elsewhere.