When businesses try to sell their product, their will be other companies that will try to lead customers into buying their product. Other companies could sell the same products as one company, but drive down the price so that people come and purchase their goods. This is an example of competition, where buyers and sellers struggle to get the "perfect price," where the highest quality goods is sold at the lowest price.
As shown in this cartoon, scarcity is a characteristic of the US Economy. Scarcity is the state in which a country cannot supply wants and needs at the same time. As things go scarce, like unicorn tears the price of the product goes up, which is a relationship of supply and demand. As the demand of unicorn tears go up and the supply of tears go down, the price goes up.
The U.S. also has economic freedom. This means that everyone has the right to decide what to spend their moneys on. Because of this, we are very diverse, and have a wider range of things to choose from. We can control our creativity unlike when a nation only supplies one type of product to sell.