Package broadly refers to two things: 1) a usable unit/component of built/compiled software, or 2) a partition of the global namespace (Java).
Package may refer to a software component or the action of creating a package. The component could be a portion of a whole system, or the whole system itself, or any level of granularity between. Typical packaging mechanisms include: tar, jar, zip, rpm, war, exe. In this context it may also be used as a verb: "I was packaging my software and...".
Package is also a term from the java world to refer to the mechanism used to partition the global namespace with the intention of making it possible of having two classes with the same name and of creating a logical structure in which classes may be held. In java packages are most commonly represented by directories. Package is also a java keyword used at the start of a class file to indicate the package to which the class belongs. This is important because of 'package' scoped access rules, which allow classes in the same package to access a field/method/class.
Because of the ambiguity here it is best to use other tags to help define the meaning of this one. If you're asking about java packages, please include the Java tag. If you're asking about packaging up your software for deployment/use add other appropriate tags, such as 'Maven', 'Make', 'Ant', etc.
