This policy setting turns off Adobe Flash in Internet Explorer and prevents applications from using Internet Explorer technology ...

This policy setting turns off Adobe Flash in Internet Explorer and prevents applications from using Internet Explorer technology to instantiate Flash objects.
 
If you enable this policy setting, Flash is turned off for Internet Explorer, and applications cannot use Internet Explorer technology to instantiate Flash objects. In the Manage Add-ons dialog box, the Flash status will be 'Disabled', and users cannot enable Flash. If you enable this policy setting, Internet Explorer will ignore settings made for Adobe Flash through the "Add-on List" and "Deny all add-ons unless specifically allowed in the Add-on List" policy settings.  
 
If you disable, or do not configure this policy setting, Flash is turned on for Internet Explorer, and applications can use Internet Explorer technology to instantiate Flash objects. Users can enable or disable Flash in the Manage Add-ons dialog box. 

Note that Adobe Flash can still be disabled through the "Add-on List" and "Deny all add-ons unless specifically allowed in the Add-on List" policy settings, even if this policy setting is disabled, or not configured. However, if Adobe Flash is disabled through the "Add-on List" and "Deny all add-ons unless specifically allowed in the Add-on List" policy settings and not through this policy setting, all applications that use Internet Explorer technology to instantiate Flash object can still do so. For more information, see "Group Policy Settings in Internet Explorer 10" in the Internet Explorer TechNet library.