Coins are one form of cash used in most countries in the world today. Coins are generally small, flat, thin, metallic, shapes used to represent various values of money. The value a given coin holds depends on its appearance, in terms of pattern, shape, size and so on. Although several countries may all use coins in general, these coins cannot be used between countries unless a currency exchange takes place. Australian currency consists of several coins of different denominations. Our silver coins aren't made of silver, and in fact are made of cupro-nickel.