The value of the dollar affects how much stuff the US buys and sells with other countries. If the dollar goes down, US exports go up because they become cheaper for other countries. But US imports don't change much because US prices don't move as much with the dollar. This means US exporters make the same money, and US consumers don't pay more for imports. Other countries that use dollars in their trade also feel the effects of dollar changes, even if they're not trading directly with the US.