What was the most important division concerning trade?

The most important division concerning trade historically has often been between free trade and protectionism. Free trade advocates argue that reducing tariffs and barriers enhances economic efficiency, stimulates growth, and fosters international cooperation. In contrast, protectionism emphasizes safeguarding domestic industries from foreign competition through tariffs and quotas, often to protect jobs and national security. This division shapes economic policies and international relations, influencing global trade dynamics significantly.