An accounting method is a set of rules under which revenues and expenses are reported in financial statements. The choice of accounting method can result in differing amounts of profit being reported in the short-term. Over the long-term, the choice of accounting method has a reduced impact on profitability.
The primary accounting methods are the accrual basis of accounting and the cash basis of accounting. Under the accrual basis, revenue is recognized when earned, and expenses are recognized when consumed. Accrual basis accounting is required for publicly-held entities, and for any organization that wants to have its financial statements audited. This is considered the most theoretically correct accounting method, but also requires a greater knowledge of accounting, and so is less likely to be used by smaller organizations.
The other main accounting method is the cash basis of accounting. Under the cash basis, revenue is recognized when cash is received from customers, and expenses are recognized when cash is paid to suppliers. This method is more likely to result in lumpy profitability in any given period, since a large cash inflow or outflow can sharply alter profits.
There are also variations on the cash and accrual methods that are considered to be hybrid accounting methods. These may be allowable under special circumstances, but will not normally result in financial statements that can be audited.