* Packages are perl files with .pm extn and is considered a separate namespace. So a package is nothing but group of related scalars,arrays,hashes and subroutines for a
specific purpose.
Once a package is included in a .pl file
(using "use") and you want to call one of the subroutines
of the package, you may have to use the scope resolution
operator &package::subroutine1
* Modules are packages but which has the capabilities of
exporting selective subroutines/scalars/arrays/hashes of
the package to the namespace of the main package itself. So
for the interpreter these look as though the subroutines
are part of the main package itself and so there is no need
to use the scope resolution operator while calling them.