Cybersecurity Explained is a comprehensive and accessible guide designed to equip readers with the knowledge and practical insight needed to understand, assess, and defend against today's evolving cyber threats. Covering 21 structured chapters, this book blends foundational theory with real-world examples-each chapter ending with review questions to reinforce key concepts and support self-paced learning. Topics include: Chapter 1-2: An introduction to cybersecurity and the threat landscape, including threat actors, attack vectors, and the role of threat intelligence. Chapter 3: Social engineering tactics and defense strategies. Chapter 4-5: Cryptography fundamentals and malware types, vectors, and defenses. Chapter 6-7: Asset and vulnerability management, including tools and risk reduction. Chapter 8: Networking principles and network security across OSI and TCP/IP models. Chapter 9: Core security principles such as least privilege, defense in depth, and zero trust. Chapter 10: Identity and access management (IAM), including IGA, PAM, and modern authentication. Chapter 11: Data protection and global privacy regulations like GDPR, CCPA, and sovereignty issues. Chapter 12-13: Security frameworks (NIST, ISO, CIS Controls) and key cybersecurity laws (NIS2, DORA, HIPAA). Chapter 14-16: Penetration testing, incident response, and business continuity/disaster recovery. Chapter 17-18: Cloud and mobile device security in modern IT environments. Chapter 19-21: Adversarial tradecraft (OPSEC), open-source intelligence (OSINT), and the dark web. Written by Anders Askåsen, a veteran in cybersecurity and identity governance, the book serves students, professionals, and business leaders seeking practical understanding, strategic insight, and a secure-by-design mindset.