Money

Money is what one buys goods and services with - and which one accepts in return for one's own goods or services.

When used this way, money serves as a medium of exchange. There are other media which can serve this same purpose.

When one calculates the price of one thing relative to another, to figure out how many eggs, say, must be traded for one chicken, there must be a smallest possible unit, like "one cent" or "one peso", so everything can be priced easily by comparison. Even if no money is used, the calculation can occur as if it was - this is called having a unit of account.

When saved in its coin or paper form, money is also a store of value - something that is trusted to still be valuable later on when there is a need to buy things one needs. It is common to trust the U.S. dollar in this way, and gold or silver coin if these are available.

When saved in a bank, or lent to someone in return for interest, what one will get back, later, the amount one will get at a certain time horizon is usually stated in money - this makes it a standard of deferred payment. In many cases, it is important which kind of money one agrees to take later on as the payment of the debt - "legal tender".

If something does not do all four functions above, it is not usually called money, but might be some other kind of financial capital. Buying things which are "just as good as money" involve some risk. People often lie and say it doesn't. Money comes in different amounts