Ethical Hacking, also known as penetration testing, intrusion testing, or red teaming, is the controversial act of locating weaknesses and vulnerabilities of computer and information systems by duplicating the intent and actions of malicious hackers.
Ethical Hackers, also known as a whitehat hacker, or simply a whitehat, is a security professional who applies their hacking skills for defensive purposes on behalf of the owners of information systems. Nowadays, certiﬁed ethical hackers are among the most sought after information security employees in large organizations such as Wipro, Infosys, IBM, Airtel and Reliance among others.
Ethical hackers looks to answer the following four basic questions during ethical hacking:
Ethical hackers operate with the knowledge and permission of the organization for which they are trying to defend. In some cases, the organization will neglect to inform their information security team of the activities that will be carried out by an ethical hacker in an attempt to test the effectiveness of the information security team. This is referred to as a double-blind environment. In order to operate effectively and legally, an ethical hacker must be informed of the assets that should be protected, potential threat sources, and the extent to which the organization will support an ethical hacker’s efforts.
Source : WikiPedia