Difference between a declared hash and stored one with storable.

mohan2monks has asked for the wisdom of the Perl Monks concerning the following question:

HI
I have a script that generates report, the scripts gets data represented as codes, the definitions for these are static.
e.g. data has city codes like NYC and i have a hash which look like

my $bighash={
NYC =>{CITYNAME=>'NEW YORK',STATE =>'', PROVINCE=>'' ...},
...
...
...

};
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As this hash is static i have defined it like above and saved to a file to disc as cityhash.pl
I have other such data hashes which i have declared and saved to files on disc.
I require those in my code when that data is to be decoded like

require "cityhash.pl"
$bighash->{$citycode}->{CITYNAME} #access name and other information l
+ike this
[download]

What is the difference in this approach and using a storable module to store this hash once and then use that as required.
Is there any benefit to memory consumption with storable as it stores data in binary format.
Please suggest if there is another approach to this. This currently is a CGI script and will also be trying make it work under mod_perl.
Pointers in that direction are welcome.

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