/skins_site folderThis folder holds the skins that apply to the whole site (i-e, not specific to a particular blog or type of blog).
Each available skin can be found in its own subfolder. You can install/create additional skins by copying/creating new subfolders into the /skins folder.
This folder holds a set of default behavior include files for several functions. For example /skins_site/_xxx.php can be overridden by /skins_site/skin_name/_xxx.php.
This folder needs to be accessed through the web.