Each node under **Configuration Properties** is called a Rule. A Rule sometimes represents a single tool like the compiler, but in general the term refers to something that has properties, that executes and that may produce some output. Each rule is populated from an xml file in the VCTargets folder. For example, the C/C++ rule that is above is populated by `cl.xml'.

MSBuild is the default project system in Visual Studio; when you choose **File | New Project** in Visual C++ you are creating an MSBuild project whose settings are stored in an XML project file that has the extension `.vcxproj`. The project file may also import .props files and .targets files where settings can be stored. In most cases, you never need to manually edit the project file, and in fact you should not edit it manually unless you have a good understanding of MSBuild. Whenever possible you should use the Visual Studio property pages to modify project settings. However, in some cases you may need to modify a project file or property sheet manually. For those scenarios, this article contains basic information about the structure of the file.

In the IDE, when you set the UseOfAtl property in the general property page, it is written to the Configuration property group in the project file, while the TargetName property in the same property page is written to the label-less property group. Visual Studio looks at the property page's xml file for the information on where to write each property. For the General property page, that file is `%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\VC\VCTargets\1033\general.xml`. The property page XML file defines the static information about a Rule and all its properties. One such piece of information is the preferred position of a Rule property in the destination file (the file where its value will be written). The preferred position is specified by the Label attribute on the project file elements.