Explain:-
Chomp
Chop
CPAN
TK

Chomp

A Chomp function removes the last character from an expr or each element of list if it matches the value of $/. This is considered to be safer than Chop as this removes only if there is a match.

Chop
A Chop function removes the last character from EXPR, each element of list.

CPAN

CPAN is the Comprehensive Perl Archive Network, a large collection of Perl software and documentation. CPAN.pm is also a module in Perl which is used to download and install Perl software from the CPAN archive.

TK

TK is an open source tool kit that is used to build web based applications using Perl.