Why to Execute Death Penalty, or Not: Phenomena of Death Penalty and Punishment

To somehow detailed discussion regarding issue of death penalty and its abolition; which is specifically a burning political and social issue for states worldwide, including discussion of Punishment relating to State's Criminal Law. This is a little and tiny effort to dilate upon issue of Death Penalty, its reasons for execution and its reasons for abolition; and what is punishment and how it relates with State's Criminal Law.