Explanation/Reference:
Explanation:
Network policies are sets of conditions, constraints, and settings that allow you to designate who is authorized to connect to the network and the circumstances under which they can or cannot connect.
Network policies can be viewed as rules. Each rule has a set of conditions and settings. Configure your VPN server to use Network Access Protection (NAP) to enforce health requirement policies.

References:
http://technet.microsoft.com/en-us/library/hh831683.aspx
http://technet.microsoft.com/en-us/library/cc754107.aspx
http://technet.microsoft.com/en-us/windowsserver/dd448603.aspx
http://technet.microsoft.com/en-us/library/dd314165(v=ws.10).aspx
http://technet.microsoft.com/en-us/library/dd469733.aspx
http://technet.microsoft.com/en-us/library/dd469660.aspx
http://technet.microsoft.com/en-us/library/cc753603.aspx
http://technet.microsoft.com/en-us/library/cc754033.aspx
http://technet.microsoft.com/en-us/windowsserver/dd448603.aspx