3. package android
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 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 android package, because they
may change between platform versions, causing unforeseen
conflicts with your design. Typically, styles are the only
resources you should use directly from these resources.
For information about using resources, see the Application
Resources developer guide.
