Moves map directories and related files to use a different set of maps.
This might be tricky to understand. I use multiple map folders to handle different map packs so they are not mixed into one. This feature is an option and you do not need to use it.
I used to use symlinks though usually need to be admin to make them. So now I move the folders around. A move on the current drive is just a change in the master file table and so the files and folders do not actually physically move.
In the Maps directory, you may have Maps and MiniMaps folders. You can add folders like Default, Demo... and inside those folders will be Maps and possibly MiniMaps.
In the image you may see a listbox with folder names. If NewMaps is selected and click the Continue button, then Maps and MiniMaps will be moved into the folder they belong to and Maps and MiniMaps inside NewMaps will be moved into the root directory. Also any Worldbuilder save files will be moved to remain in sync with the Maps.
This seems to work OK, though may affect things like the games replay feature or another feature.
On selection, some other buttons may show to view readme.txt. Also a button for map cache details. So you can know what you are selecting. As the image shows, map count is done and you know what is the current Maps folder is in use.
Suggest testing with copies, and if good, then go for it. This should only be used by those users willing to accept the risks of having multiple maps folders.