The term "buck" is a colloquial expression for the United States dollar, often used in everyday conversation. It originated in the 18th century when deer skins, or "bucks," were used as a medium of exchange. Today, the dollar is the official currency of the United States and is denoted by the symbol $. The dollar is further divided into 100 smaller units called cents. It is widely used in international trade and is considered a global reserve currency, meaning many countries hold it as part of their foreign exchange reserves. The $ is also used in various contexts, such as pricing goods and services.