Britannica Educational Publishing 
Money and Capital [PDF ebook] 

Money can be paper or metal, can come in dollars, euros, pesos, or one of many other forms of currency, and can be used to pay for goods and services. Explanations of topics such as how we determine value, what exactly capital is and how it relates to money, and more are examined through accessible text. The gold standard, various currencies from around the world, and interest theory are also covered.