profit is not cash
Suppose you sell a friend a 1,000 bicycle and agree she will pay you next month. The moment of the sale, you are 1,000 'richer' in the sense that you earned it — but your wallet is empty until she actually pays. Meanwhile your rent is due today. You can be profitable and broke at the same time. That gap — between having earned money and having the cash in hand — is the whole idea behind 'profit is not cash.'
Profit (net income) is measured on the accrual basis: revenue is recorded when it is earned and expenses when they are incurred, regardless of when cash moves. Cash flow tracks the actual movement of money. The two diverge for concrete reasons: a credit sale adds to profit before any cash arrives (accounts receivable); buying inventory uses cash before any profit is recorded; depreciation reduces profit without using cash; and repaying a loan uses cash without reducing profit. None of these are errors — they are the accrual system working as designed.
Grasping this is the single most important insight the cash flow statement teaches, and it is why three financial statements exist rather than one. Many businesses fail not because they are unprofitable but because they run out of cash — fast-growing firms are especially vulnerable, since growth ties up ever more cash in receivables and inventory even as reported profit rises. The practical lesson: watch profit and cash together, and never assume one tells you the other.
A growing distributor reports record profit of 200,000, yet its cash falls during the year because it sold heavily on credit (receivables jumped 150,000) and stocked up inventory (up 120,000). On paper it thrived; in the bank account it nearly ran dry.
Record profit, shrinking cash — the classic trap the cash flow statement reveals.
The reverse also happens: a company can post a net loss yet still have positive cash flow (heavy depreciation plus customers paying down old receivables). Profit and cash are simply two different questions.