Windows Explorer is the application included in Windows that allows you to look for files and see the folder structure on your storage devices (disks, CDs, DVDs, Flash drives, etc.)
Although the names are almost the same Windows Explorer and Internet Explorer are two totally different applications. Internet Explorer is the Microsoft Internet browser.
There are several ways you may use Windows Explorer.(sometimes just called Explorer but can be a confusion with Internet explorer). The first that almost everyone uses Windows Explorer (and usually do not realize it) is when they get a browse window to find a file on their computer. That browse window is part of Windows Explorer.
The second way people may use it is by clicking Computer (or My Computer depending on Windows version) and then they see their storage drives and can go in them to see folders and files.
The third way is to right click the Start button (not sure if works in Windows 8) and choose Open Windows Explorer. You can then go to Computer and go in storage drives or go to special folders like Documents