Contains resource classes used by applications included in the platform and defines application permissions for system features.
You can use some resources directly from these {@link android.R} classes in your own applications, but you should generally use only resources that you've provided directly in your application, in order to provide a cohesive application package that has no external dependencies. In particular, you should not use drawable resources from the {@code android} package, because they may change between platform versions, causing unforeseen conflicts with your design. Typically, {@link android.R.style styles} are the only resources you should use directly from these resources.
For information about using resources, see the Application Resources developer guide.