The term money has two very different meanings in popular discourse. We often speak of someone "making money," when we really mean that he or she is receiving an income. We do not mean that he or she has a printing press in the basement churning out greenbacked pieces of paper. In this use, money is a synonym for income or receipts; it refers to a flow, to income or receipts per week or per year. We also speak of someone's having money in his or her pocket or in a safe-deposit box or on deposit at a bank. In that use, money refers to an asset, a component of one's total wealth. Put differently, the first use refers to an item on a profit-and-loss statement, the second to an item on a balance sheet
Milton Friedman