Hi pusnsuresh,
1. Impersonation is when ASP.NET executes code in the context of an authenticated and authorized client
http://msdn2.microsoft.com/en-us/library/aa292118(VS.71).aspx
2. Code access security is a resource constraint model that allows administrators to determine if and how particular code is able to access specified resources and perform other privileged operations.
http://msdn2.microsoft.com/en-us/library/aa302425.aspx
Sincerely,
Benson Yu
Microsoft Online Community Support
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