The real definition for hacking is act of thinking differently and making a system to work beyond what indented for. Now a days, it is being referred as act of gaining unauthorized access to a system. Ethical hacking is a term coined by IBM meant to imply a broader category than just penetration testing. The definition of an Ethical Hacker is very similar to a Penetration Tester. A Certified Ethical Hacker has obtained a certification in how to look for the vulnerabilities and weaknesses in target systems and uses the same knowledge and tools as that of a hacker. An Ethical Hacker is usually employed by an organization who totally trusts him or her to attempt to penetrate networks and/or computer systems, using the same methods and tools as a hacker, for the purpose of finding and fixing computer security vulnerabilities. Unauthorized hacking ( gaining access to computer systems without any authorization from the owner) is a crime in most countries, but penetration testing done by request of the owner of the system or network is not a crime.