Divisible - You have to be able to divide it up into smaller portions without considerable work. Spanish pieces of eight were often cut into bits. Two bits equaled a quarter of a dollar. Durable - Don't have to replace it often. It won't easily wear and tarnish.
Credit is a method of exchange of labor in lieu of money.
Rather than wait until you have gathered the necessary money by working the hours, you can pledge your future labor as a guarantee towards that obligation and get the car now. It could be said that credit is simply a state of mind that all will honor their obligations. Debt is what you create from a credit transaction and are obligated to pay back. Credit and debt walk hand in hand. However, the levels of credit and debt are often not equal.