Cash flow

The movement of money into and out of a business over a specific period, tracking when cash is received from customers and when it's paid out for expenses. Positive cash flow means more money coming in than going out.

First used in business contexts in the 1950s, literally describing money 'flowing' like water through a business. The hydraulic metaphor, combining 'cash' from French 'caisse' (money box) with 'flow' from Old English 'flowan,' helps visualize money's movement through an organization.