This chapter introduces the study of criminology, focusing on understanding crime, criminal behavior, and justice systems from social, psychological, and biological perspectives. It explains criminology’s evolution—from Enlightenment thinkers advocating fairness to modern multidisciplinary approaches integrating sociology, psychology, and data analysis. The chapter also highlights criminology’s practical applications in crime prevention, policy development, law enforcement, and rehabilitation. The discussion then transitions into victimology, a subfield emphasizing the experiences, needs, and rights of victims, exploring causes and impacts of victimization, victim-offender relationships, and societal responses.