If present, this file is a part of the package named packageName and must appear in an appropriately named sub-directory.

import importableObject;

Import statements do not affect visibility. They serve only to allow more concise naming, i.e., elimination of packageName before a class or interface name reference.

importableObject may be either packageName.ClassOrInterfaceName or packageName.
The first form allows ClassOrInterfaceName to be used as a shorthand for packageName.ClassOrInterfaceName ; the second allows any (visible) names within packageName to be used without explicitly giving the packageName.