CEH (Certified Ethical Hacker) is an EC-Council certification covering offensive-security and ethical-hacking techniques. It validates knowledge of how attackers probe systems so defenders can find and fix weaknesses, organized around EC-Council's published exam blueprint.
What it means
EC-Council publishes a free CEH exam blueprint defining the covered domains (such as reconnaissance, scanning, system hacking, web and network attacks, and related tools and methods). It is a vendor-defined offensive-security credential; EC-Council's training is paid. The credential teaches attacker techniques used in authorized testing.