Cash flow is the movement of money into or out of a business, project, or financial product. It is usually measured during a specified, limited period of time. Measurement of cash flow can be used for calculating other parameters that give information on a company’s value and situation. Cash flow can be used, for example, for calculating parameters: it discloses cash movements over the period. It is used to determine a project’s rate of return or value. The time of cash flows into and out of projects are used as inputs in financial models such as internal rate of return and net present value. It is used to determine problems with a business’s liquidity. Being profitable does not necessarily mean being liquid. A company can fail because of a shortage of cash even while profitable. It is used as an alternative measure of a business’s profits when it is believed that accrual accounting concepts do not represent economic realities. For instance, a company may be notionally profitable but generating little operational cash (as may be the case for a company that barters its products rather than selling for cash). In such a case, the company may be deriving additional operating cash by issuing shares or raising additional debt finance. Cash flow can be used to evaluate the ‘quality’ of income generated by accrual accounting. When net income is composed of large non-cash items it is considered low quality. It is also used to evaluate the risks within a financial product, e.g., matching cash requirements, evaluating default risk, re-investment requirements, etc. Cash flow notion is based loosely on cash flow statement accounting standards. It’s flexible as it can refer to time intervals spanning over past-future. It can refer to the total of all flows involved or a subset of those flows. Subset terms include net cash flow, operating cash flow and free cash flow.