“All squares are rectangles, but not all rectangles are squares.”
That idea really confounded me as a child learning geometry. How could one belong to another, yet the inverse not be true? As my teacher explained, the difference lies in specificity.
A similar concept applies in exporting: If you’re new to exporting, the difference between Harmonized System (HS) numbers and Schedule B codes may be vexing. You may be wondering, are they the same? Can they be used interchangeably? What’s the difference?