A trillion is a numerical value represented by the digit 1 followed by 12 zeros, or 1,000,000,000,000. It is a part of the metric system and is commonly used to quantify large amounts, such as national debts, budgets, or the number of stars in the universe. In the United States, a trillion is often used in discussions about the economy and government spending. In the context of finance, trillions can refer to the total value of assets, investments, or market capitalization of companies. For example, the global economy is often measured in trillions of dollars, highlighting the vast scale of financial transactions and economic activity worldwide.