Features and Requirements
A feature can be a property (for example, a kernel mode device driver), a bus, an interface, or capability (for example, a device that prints) of a target. Feature objects contain a list of requirements that are children of the Feature. Use the TargetType property to determine whether a feature applies toward a specific target.
A requirement (for example, "all PCI devices must do x") maps to only one feature. Tests are mapped against requirements, so if a feature is found, you must run all the corresponding tests for its requirements.
A feature can apply to only a subset of operating system versions or platforms. For example, a requirement might apply to only Windows® 7 x86, or to it might apply to Windows 8 (x86) and Windows 8 (x64) (but not Windows Server® 2012).