Definition
Cashflow is the literal sum of cash arriving (from customers, loans, investment) and cash leaving (to suppliers, staff, tax authorities, lenders) in a period. Positive cashflow means more came in than went out; negative cashflow means the opposite.
Cashflow is not the same as profit. A business can be profitable on paper and run out of cash because customers pay slowly, inventory is tied up, or the business is investing ahead of revenue. The reverse also happens — a loss-making business with very long payment terms to suppliers can be cashflow positive for a while.
Why it matters
Most small business failures are cashflow failures, not profit failures. The business 'runs out of money' before customers pay, and cannot meet payroll, rent, or tax. Watching cashflow as carefully as profit — and forecasting it 30, 60, and 90 days ahead — is the single most important habit a small business can build.
Where this appears in your tools
Cashflow is the underlying concern behind the Tax Survival Calculator (reserve before you spend), the Profit Leak Analyzer (find the leaks), and the Late Payment Recovery Bot (turn AR into cash).