A package in Java is a collection of related classes and interfaces that share a common namespace. A namespace is a set of unique names that identify the components of a package.

Java implementations map package and subpackage names to same-named directories. For example, an implementation would map graphics to a directory named graphics.

The Java 2 SDK organizes its vast collection of classes and interfaces into a tree-like hierarchy of packages within packages, which is equivalent to directories within directories.

Dot notation for package names The convention for packages is different from the Java naming conventions used for variables, methods and reference types. Packages are always written in lowercase ...