The purpose behind Perl modules is to create code that can be loaded into another Perl script. This technique is often referred to as creating a library.
Perl modules consist of a set of related functions. By itself, a Perl module doesn’t "do" anything. By calling a Perl module, your script will have access to additional functions and variables.
Some general guidelines for modules:
The filename’s extension should be ".pm".
All identifiers in your module should be placed in a separate package (not main) to avoid the possibility of overwriting existing ...
