A package is a separate name space for variables to reside in.

  

    package Nothing;

    sub doNothing
    {
       print "This package does nothing!\n";
    }

    1;

1.	Contents of the symbol table for the main package.
2.	Default package is main
3.	Define variables with the same name in different package
4.	Module::get_scalar()
5.	Out value scope
6.	Package declarations and subroutine
7.	Reference variable by package name
8.	Requires the package created above and calls the subroutine declared within it:
9.	Scope change
10.	Switches between packages.
11.	This code should be stored in the file Mymodule.pm.
12.	Using the package keyword to change the package context
13.	You have to tell Perl which packages you intend to use, with the use command:
14.	Your package

A package is a separate name space for variables to reside in. : Package « Language Basics « Perl