In accounting, cash flow is the difference in amount of cash available at the beginning of a period (opening balance) and the amount at the end of that period (closing balance). It is called positive if the closing balance is higher than the opening balance, otherwise called negative. Cash flow is increased by (1) selling more goods or services, (2) selling an asset, (3) reducing costs, (4) increasing the selling price, (5) collecting faster, (6) paying slower, (7) bringing in more equity, or (8) taking a loan.