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.he total net cash flow is the sum of cash flows that are classified in three areas: 1  Operational cash flows: Cash received or expended as a result of the company's internal business activities. 2  It includes cash earnings plus changes to working capital.