Knowledge is Power!
In a security context, a Hacker is someone involved in computer insecurity, specializing in the discovery of exploits in systems (for exploitation or prevention), or in obtaining or preventing unauthorized access to systems through skills, tactics and detailed knowledge. Sometimes, "hacker" refers to a black hat hacker (a malicious or criminal hacker). There are also ethical hackers (more commonly referred to as white hats), and those more ethically ambiguous (grey hats). To disambiguate the term hacker, often cracker is used instead, referring either to computer security hacker culture as a whole to demarcate it from the academic hacker culture (or specifically to make a distinction within the computer security context between black hat hacker and the more ethically positive hackers (commonly known as the white-hat hackers). The context of computer security hacking forms a subculture which is often referred to as the network hacker subculture or simply the computer underground. According to its adherents, cultural values center around the idea of creative and extraordinary computer usage. Proponents claim to be motivated by artistic and political ends, but are often unconcerned about the use of criminal means to achieve them.
While hacker may mean simply a person with mastery of computers; however the mass media most often uses "hacker" as synonymous with a (usually criminal) computer intruder. It's completly false. In computer security, several subgroups with different attitudes and aims use different terms to demarcate themselves from each other, or try to exclude some specific group which which they do not agree.
A white hat hacker or ethical hacker is someone who breaks security but who does so for altruistic or at least non-malicious reasons. White hats generally have a clearly defined code of ethics, and will often attempt to work with a manufacturer or owner to improve discovered security weaknesses, although many reserve the implicit or explicit threat of public disclosure after a "reasonable" time as a prod to ensure timely response from a corporate entity. The term is also used to describe hackers who work to deliberately design and code more secure systems. To white hats, the darker the hat, the more the ethics of the activity can be considered dubious. Conversely, black hats may claim the lighter the hat, the more the ethics of the activity are lost.
A grey hat hacker is a hacker of ambiguous ethics and/or borderline legality, often frankly admitted.
A blue hat hacker is someone outside computer security consulting firms that are used to bug test a system prior to its launch, looking for exploits so they can be closed. The term has also been associated with a roughly annual security conference by Microsoft, the unofficial name coming from the blue color associated with Microsoft employee badges.
A black hat hacker is someone who subverts computer security without authorization or who uses technology (usually a computer or the Internet) for terrorism, vandalism, credit card fraud, identity theft, intellectual property theft, or many other types of crime. This can mean taking control of a remote computer through a network, or software cracking.
Script kiddie is a pejorative term for a computer intruder with little or no skill; a person who simply follows directions or uses a cook-book approach without fully understanding the meaning of the steps they are performing.
A hacktivist is a hacker who utilizes technology to announce a political message. Web vandalism is not necessarily hacktivism.
Puppet Master is the term for a hacker who uses other hackers to achieve his goals. Similair to a puppet master, they are pulling the strings around in the hacking scene. Puppet Masters are usually well skilled, and often show their power to gain respect and pulling more people to them. The term Puppet Master does not only apply for the hacking scene, it is often mixed with the carding scene as well.