Differences between "Include Directories" and "Additional include Directories" in VC2010

By right-clicking on a project, you can see that there are two places to set up the include related directories:

1. VC + + Directories Include directories
2. Additional Include Directories

Don't know what the difference is, after getting the answer on MSDN:

"VC + + Directories Include Directories": Directory settings displayed in the window is the directories that Visual Studio would search for include files referred to your source code files. Corresponds to environment variable INCLUDE. More Information:http://msdn.microsoft.com/en-us/library/t9az1d21 (v=vs.80). aspx

"Additional Include Directories": The directory to being added to the list of directories searched For include files. More information:http://msdn.microsoft.com/en-us/library/73f9s62w (v=vs.80). aspx

The following link is quite clear:

The compiler searches for directories in the following order:

1.Directories containing the source file.

2.Directories specified with THE/I option, the order is that CL encounters them.

3.Directories specified in the INCLUDE environment variable.

The/I in Order2 is set up by the Additional Include directories.

The Include in Order3 is set by VC + + directories, include directories.

Differences between "Include Directories" and "Additional include Directories" in VC2010