Double-Entry Bookkeeping
Double-entry bookkeeping dates back some 1000 years, introduced in Korea and by Jewish bankers in Egypt, then in Italian banks during the Renaissance.
The basic idea is simple: money moves from one account to another; an addition to one account must correspond to a subtraction from another account.
For example, suppose you withdraw $100 in cash from your bank account at an ATM:
Cash in Pocket | Bank Account | |
Get cash | +$100 | -$100 |
Double-entry bookkeeping provides an audit trail that allows the flow of money to be followed.