XYplorer Beta Club

I'm unable to understand what "Two Times Single Pane" means on this page: https://www.xyplorer.com/tour.php?page=dp

Screencap below. Please help me understand. Thank you.

XY has always two panes loaded but in single pane mode you only see the active pane.
By clicking on the 1 or 2 you switch between pane 1 or 2 being active and shown.

Hope this clarifies it.

"XY has always two panes loaded"

By this are we counting the tree view as one pane, and the list view as the second pane? If that's the case (then yes, I understand it). Thank you for responding.

A pane is a list pane, not the tree.

RalphM's answer explains it exactly as it is...