Money was made by people who got sick and tired of trying to figure out whether 3 loaves of bread had the same value as 3 fish. It was just a lot easier to go around saying, "These coins are made of a rare metal that has an equal value to 3 loaves of bread". Later it was found that it got pretty tiresome carrying around all these coins all the time, so someone decided to write down on paper "This paper is equal to 5 gold coins". Eventually a recognizable standard was developed that all the papers in a specific area had to be made by this group of people for that area and have different denominations on them. Then counterfeiting came along and now we carry plastic instead.