A hacker or hacker is a person who shows a passion for understanding the inner workings of systems, computers and computer networks particular.1.
In computer security, a hacker is a specialist in the control of computer security and therefore the means to defeat this safety. Some of them use this knowledge in a legal and others use off-the-law. In the latter case, we speak of informatiques2 pirates.
Hacker in meaning relayed by the mass media, refers to black hats (hacker). In order to disambiguate the term hacker, cracker is often used to refer to black hats, and delineating the academic hacker culture as defined by Eric Raymond
Computer jargon class hackers into several categories based on their objectives, competence and legality of their actions. This vocabulary refers to western movies where the hero wearing a white hat and the bad guys wear black hats. Out of respect we will use the term cracker not hacker to describe these people.
terminology
White or white hat hats: Professional IT security (security consultants, network administrators ...) performing penetration testing in accordance with their clients and the legislation in force to qualify the systems security. Some hackers themselves as white hat when they break the law, their purpose being to prevent those responsible for faults of their systems. Some of them infiltrate the toughest security systems just to knowledge, to say that they can do.
Blue caps or blue hat: computer security consultants to check for bugs and correct potential exploits before launching an operating system on the market. The term is especially used by Microsoft, designating its hackers and computer security engineers whose role is to find the Windows vulnerabilities.
Black or black hat hats: virus writers, cyber-spies, cyber-terrorists and cyber crooks, acting mostly off-the-law in order either to harm, to make a profit or to obtain information . These hackers do not have the same ethics as the White hats and often malicious. Most malware are then called crashers.
Gray or gray hat hats: they do not hesitate to enter the system without being authorized, they do not have bad intentions. This is often the "computer exploit" motivates them, a way to demonstrate their agility. This category covers the wide range of people ranging between black hat and white hat. That said, the failure to obtain prior authorization makes it unlawful.
Or lamer script kiddies, literally "kids who use scripts" without great skill, they mostly hack a desire to be noticed, using programs written by others. These people are not strictly speaking hackers, but they generally regard as such.
Hacktivists: acting in defense of a cause, they do not hesitate to break the law for attacking organizations to paralyze or obtain information.