The words "Income" and "Expense" are beguilingly simple; everyone thinks they know what they mean. The money I get is income, the money I spend is expense, right? Right! However, there are subtlties. The time that you make your income is ofen different than when you actually get the money: to ease the recording of these types of transactions, the concept of 'accounts payable' and 'accounts receivable' has been invented. Click on that link to go there. This section deals with the more basic recording of incomes and expenses.