What Are Targeting Packs?
 
	
		Microsoft provides a set of 
		“Multi-Targeting Packs”, to provide Microsoft Visual Studio and other 
		developer tools with a structured system for targeting .NET platforms. 
		The primary content of these targeting packs is reference assemblies, 
		which describe the APIs supported by a given .NET platform version. 
		Compilers and other tools and services can consume these assemblies to 
		provide a high-fidelity representation of that .NET platform version.
	Learn more about the above : http://msdn.microsoft.com/en-us/hh454951.aspx
 
 
	Complete information about the VS 2010 pack, 
	use the below link to see
 
	
	Thanks for reading :)