What is a ... site explorer?  

Overview

At the heart of Clear-Site is the site explorer. This mimics the behaviour of Windows Explorer in that it shows a 3-tier hierarchy of you current content configuration. All content created will appear on site explorer. There is a direct relationship between the ordering of the items in site-explorer and the order in which they appear in Smart-Menu. To help you manage Smart-Menu, you can move items around in the site explorer through the up and down buttons (see here) and this will take affect on Smart-Menu immediately. You can also view the selected page in the public section of your website. (See here)

You can access the properties of any of your added content items in site explorer by clicking on the blue writing for the item.