Interstate commerce refers to the trade and movement of goods, services, and resources across state lines within the United States. It involves businesses and individuals engaging in commercial activities that cross state boundaries, impacting the economy on a national level. The regulation of interstate commerce is primarily governed by the Commerce Clause of the U.S. Constitution, which grants Congress the authority to regulate such activities. This ensures a consistent framework for trade, preventing states from imposing conflicting laws that could hinder economic growth and competition.