The aim of this paper is Understanding Cybercrime: Phenomena, Challenges and Legal Response is to help everybody in understanding the legal aspects of cyber security and to assist harmonize legal frameworks. As such, it aims to assist higher perceive the national and international implications of growing cyber threats, to assess the necessities of existing national, Regional and international instruments, and to help in establishing a sound legal foundation. It provides a comprehensive summary of the foremost relevant topics joined to the legal aspects of crime and focuses on the strain of developing countries. because of the multinational dimension of crime, the legal instruments are identical for developing and developed countries