What is the difference between Standing Seam and Standing Rib?

Both Standing Seam and Standing Rib are terms that can be used interchangeably. These terms are essentially referring to the same product.

Standing Seam refers to a concealed fastening roofing system when the standing seam (or rib) conceals the fasteners. So essentially, they mean the same thing. They are both broad terms that describe a number of different profiles.