The primary distinction rests on jurisdictional boundaries. Activities crossing state lines fall under federal regulation, while those contained within a single state’s borders are governed by that state’s laws. Consider the shipment of goods: If a truck carries merchandise from California to Nevada, it is subject to federal guidelines. Conversely, a delivery originating and terminating within California is subject to California’s specific regulations.
Understanding this division is crucial for legal compliance and business operations. Historically, the need for consistent standards across state lines led to federal oversight in certain sectors. This has significant implications for commerce, transportation, and communication, ensuring a degree of uniformity and preventing individual states from creating barriers to trade.