Nuproj - Difference between and

I see in nuproj files sometimes files are included using the File node or the Content node:

<File Include="$(OutDir)\MTL\Headers\MtlStatusCodes.h"><TargetPath>inc</TargetPath></File>

OR

<Content Include="$(OutDir)\MTL\Headers\MtlStatusCodes.h"><TargetPath>inc</TargetPath></Content>

Is there a fundamental difference here? Why are there two ways to do the same thing?