Defense vs. offense, strategy vs. technique
The CISSP is built around the question "how do you design, govern, and operate secure systems?" Its eight domains span the full security lifecycle from risk management through architecture, operations, and software security. The exam emphasizes integrated judgment — choosing the answer that best balances technical, business, and regulatory considerations.
The CEH is built around the opposite question: "how do attackers actually compromise systems, and how do you replicate their techniques ethically?" Its 20 modules walk through reconnaissance, scanning, enumeration, system hacking, malware threats, sniffing, social engineering, web application attacks, wireless attacks, mobile attacks, and IoT exploitation. The exam tests recognition of tools, techniques, and attack chains rather than strategic judgment.