The document discusses ethical hacking and describes hackers. It defines ethical hacking as evaluating a system's security vulnerabilities by attempting to break into computer systems. Ethical hackers possess strong programming and networking skills and detailed hardware/software knowledge. They evaluate systems by determining what intruders can access, what they can do with that information, and if intruder attempts can be detected. The document outlines different types of hackers and classes them as black hats, white hats, gray hats, and ethical hackers based on their motivations and how they use their skills.