Imperial units are a system of measurement that originated in the British Empire and are still used in some countries today, including the United States. This system includes units such as inches, feet, yards, and miles for length, as well as pounds and ounces for weight. Unlike the metric system, which is based on powers of ten, imperial units can be less intuitive due to their varied conversion factors. For example, there are 12 inches in a foot and 3 feet in a yard, making calculations sometimes more complex for users unfamiliar with the system.