Money is what you use to buy things. The idea of trading things is very old. A long time ago, people did not buy or sell with money. Instead, they traded one thing for another to get what they wanted or needed. One person who owned many cows could trade with another person who owned much wheat. Each would trade a little of what he had with the other, and support the people on his farm. This is known as barter.
Other things that were easier to carry around than cows also came to be held as valuable, and were used as trade items, such as jewelry and spices. When people changed from trading in things like cows and wheat to using money instead, they needed things that would last a long time, still be valuable, and could be carried around. The first country in the world to make metal coins was called Lydia, sometime around 650 BC, in the western part of what is now Turkey.
The Lydian coins were made of a weighed amount of precious metal and were stamped with a picture of a lion. This idea soon spread to Greece, the rest of the Mediterranean, and the rest of the world. Coins were all made to the same size and shape. In some parts of the world, different things have been used as money, like clam shells or blocks of salt. Besides being easier to carry than cows, using money had many other advantages. Money is easier to divide than many trade goods.
If someone own cows, and wants to trade for only “half a cow’s worth” of wheat, he probably does not want to cut his cow in half. But if he sells his cow for money, and buys wheat with money, he can get exactly the amount he wants. Cows die, and wheat rots. But money lasts longer than most trade goods. If someone sells a cow for money, he can save that money away until he needs it. He can always leave it to his children when he dies. It can last a very long time, and he can use it at any time.