Between the panels are seams which are raised above the level of the metal roofing. This is where we get the term standing seam, because the seam is raised or standing, as opposed to flush-mounted.
The panels are held to the roof by a series of clips and fasteners that are below the roof panel. This is a great advantage over screw down type roof which require multiple holes to be drilled in each panel. Another advantage of standing seam metal roofs is contained in the name itself: seams, the weak point in any roof and a potential entry point for moisture, are raised above the level of the roofing panel. The joint where the panels come together (the standing seam) are mechanically seamed together to insure a water tight seal.