There was a time when gold or silver was used as money and was called money. Maybe that time is not completely gone, but very little precious metal is in circulation as money anymore. It's just not very efficient, nor feasible, for that matter. More to the point, we should not even think of this stuff as money, but rather as trade goods. You can tell that it is better classified as goods since people buy and sell it for money. It has a value of it's own. Calling it money just confuses us.
When you trade value for value, that's direct barter. When you trade value for an accounting of that value, money, it's splitting barter into two or more distinct parts, and the money is a stepping stone, or a go-between. Then the barter is no longer direct, but split or indirect barter, and we seldom refer to it as barter.
The money used to keep track of the values serves as a credit clearing mechanism. When you provide value to someone and they pay you with some form of money, you are, really, accepting credit as payment. You are not receiving value now, but only the promise of value delivered in the future. This requires trust, if not in the buyer, at least in the money the buyer gives you. You must trust that someone (else?) will also accept the money as payment when you buy from them.