A black hat hacker is an individual with very extensive computer knowledge, whose purpose is to breach or bypass your any type of internet security. Black hat hackers are also known as Crackers or Dark-Side Hackers. In the general view is that, while Black Hat hackers build things, crackers break things. They are computer security Hackers that break into computers and networks or also create computer viruses, Trojans, or Spyware etc. The term of “Black Hat” comes from old westerns where the bad guys usually work Black hats and the good guys work White ones.
White hat hackers also identify security weaknesses, But, instead of performing malicious attacks and theft, they expose the security flaw in such a way as to alert the owner that there is a breach so they can fix it before a black hat hacker can take advantage of it. Though they often start out as Black Hat Hackers, White Hat Hackers sometimes are paid consultants or actual employees of a company that needs its systems protected. Other types of hackers include: Blue Hat Hackers & Gray Hat Hackers.
Blue Hat Hackers are security professionals that are invited by Microsoft to expose vulnerabilities in Windows products.
Gray Hat hackers are hackers that perform both malicious activities and helpful ones.