The Windows Shell is the main graphical user interface in Windows hosted by Windows Explorer. It also implements a shell namespace that enables computer programs running on Windows to access the computer's resources via the hierarchy of shell objects.
The Windows Shell is the main graphical user interface in Windows hosted by Windows Explorer. Important features of Windows Shell include the Desktop, Taskbar, Start Menu, et cetera. Extending functionality of Windows Shell is possible using shell extensions.
In the shell namespace hierarchy "Desktop" is the top object; below it there are a number of files and folders stored on the disk, as well as a number of special folders whose contents are either virtual or dynamically created like the Recycle Bin, Libraries, Control Panel, This PC and Network.
Read more regarding the Windows Shell here: