Penal law is the field of public law which studies crime and punishment notions, divides into two as general and private penal laws. General penal law studies definition of crime with its material and moral elements, general principles that determine penal law, definition of punishment, deletory reasons of a crime, reductive and deletory reasons for punishment etc, such principles and theories which is effective for all kinds of crimes. Private penal, on the other hand, studies which acts count as crime with regard tp that country's law codes, their scope and limitations, their differences and possible punishments for these crimes. In broad aspect, penal law includes criminal justice system as well, but if we narrow down our aspect, criminal justice system stays outside of penal law.