Basics of the Security Policy System

Flash policy file
• The existing crossdomain.xml policy file used by Adobe Flash.
•This policy file can only be used by the WebClient and HTTP classes in the System.Net namespace.
•A Flash policy file must allow access to all domains to be used by the Silverlight 2 runtime.

Silverlight policy file
•The Silverlight policy file that can be used by the WebClient and HTTP classes in the System.Net namespace and also by the sockets classes in the System.Net.Sockets namespace.
• This policy file has a different format than the Flash policy file.