This textbook is dedicated to an in-depth study of modern global security problems such as cybercrime and cyberterrorism. It provides a detailed analysis of the concept, development and inextricable link between cybercrime and technological progress. Cybercrime is a serious threat to states and societies today, as it not only leads to theft of personal information and economic damage, but also negatively affects national security and international stability. The guide covers legal issues related to cybercrime from an international and national perspective The importance of international legal mechanisms such as the Budapest Convention and their role in ensuring global cybersecurity is widely covered. It also provides a comparative analysis of the national legal systems of the United States, the European Union, China, Russia, India and other countries, and examines their strategies for combating cybercrime. In particular, the approaches adapted to the political and social needs of different countries reveal the complexities of combating cybercrime and cyberterrorism. One of the important aspects of this guide is the analysis of modern approaches to technological countermeasures against cybercrime and cyberterrorism, including artificial intelligence, encryption technologies, and securing IoT devices. The guide uses real-life examples to illustrate the negative impact of cybercrime and cyberterrorism on state infrastructure, financial systems, and society. For example, major incidents such as the attack on Colonial Pipeline highlight the need to reconsider cybersecurity strategies.