They are both the same panel, known as simply a standing seam panel, or a mechanical lock panel. One side of the panel has the male lock while the other has the female lock.
To put these panels together, the female lock is placed over the male portion of the panel. When the first portion of the female lock is folded, that creates a
single lock, which is a horizontal lock. If the second portion of the female lock is also bent, that creates a double lock, which is a less visible, vertical lock.
Double lock is the choice of most because of its longevity and looks.