There are all kinds of things that can be used as money. Anything that is commonly accepted within an economy to be used as means of exchange, unit of accounting, a store of wealth, etc. can be used. Money is, as money does. Money is a human construct to make exchange of goods and services easier.
Currency, not money. Money must be a currency, but not all currency is money. Fiat dollars and Bit Coins, while currencies, fail the standard for money with regard to durability and store of value. They also have no underlying utility.
