Standing seam metal roofing is a concealed fastener metal panel system that has 2 vertical ribs and a broad, flat area between them. It can  also be described as having raised seams, or vertical legs, that rise above the panel’s flat area. Standing seam systems can be used for either metal roofing, which is the most common, or metal walls.
The most important feature of  standing seam systems is that the fastener is hidden, whether the panel is attached to the roof deck using a clip or is directly fastened to the decking material using a concealed fastener flange.