The contemporary IT landscape is littered with various technologies that vendors claim will "solve" an organization's cybersecurity challenges. These technologies are powerful and, in the right context, can be very effective. But misunderstood and misused, they either do not provide effective protection or do not protect the right things. This results in unnecessary expenditures, false beliefs of security, and interference with an organization's mission. This book introduces major technologies that are employed in today's cybersecurity landscape and the fundamental principles and philosophies behind them. By grasping these core concepts, professionals in every organization are better equipped to know what kind of technology they need, ask the right questions of vendors, and better interface with their CISO and security organization.