Ethical hacking can be stated as the methodology that ethical hackers adopt to discover live vulnerabilities in information systems, operating environments. These usually employ the same tools and techniques as criminal attackers, but they neither damage the target systems nor steal information, in doing so maintaining the integrity and confidentiality of the system. Their job is to calculate the security of targets, provide updates concerning any discovered vulnerabilities, and advise proper mitigation measures.
An ethical hacker is a computer & network expert who has an ability to pound attacks on security systems on behalf of its owners, in quest of vulnerabilities that a malevolent hacker could exploit. To test a security system, ethical hackers use the same methods as their less righteous counterparts, but report problems instead of taking advantage of them. Ethical hacking is also known as penetration testing, intrusion testing and red teaming.