Certified Ethical Hacker (CEH) is a qualification obtained by demonstrating knowledge of assessing the security of computer systems by looking for weaknesses and vulnerabilities in target systems, using the same knowledge and tools as a malicious hacker, but in a lawful and legitimate manner to assess the security posture of a target system.
Certified Ethical Hacker CEH v11 will teach you the latest commercial-grade hacking tools, techniques, and methodologies used by hackers and information security professionals to lawfully hack an organization.
Source: https://www.eccouncil.org/programs/certified-ethical-hacker-ceh/