Broadly speaking, hackers can be classified into three different types -

• Black Hat Hacker

Black hat hackers are involved in unethical hacking and they often try to break into computers or computer networks by sharing viruses or malicious links. They aim to find the potential errors or loopholes in the system and then take advantage of that information to come up with an attack. They often hack systems by gaining unauthorized access in pursuit of financial gains. They do so by stealing your private information such as banking details or credit card information. They can also modify data on your system, compromise it or even sell it. Black hat hacking is an illegal and punishable offense in several countries.

• White Hat Hacker

White hat hackers, as discussed above, are ethical hackers or IT experts of right thinking. They can be privately hired by an organization for penetration testing and transparently report any flaws or weak points they find in the system. Ethical or white hat hacking is legal.   

• Gray Hat Hacker

Also spelled as Grey hat hackers, they often engage in hacking a system without having prior permission or access but without any malicious intent. A hybrid of black and white hat hackers, they do not follow ethical hacking principles but test the security of the system and often tell the administrator about it. They have no intention of damaging the system or any financial motives. Grey hat hacking may be a punishable offense depending on the system they hack and the disclosure of their vulnerabilities.