Types of Hackers on the basis of activities performed by them.

White Hat Hacker:- A White Hat Hacker is computer guy who perform Ethical Hacking. These are usually security professionals with knowledge of hacking and the Hacker toolset and who use this knowledge to locate security weaknesses and implement counter measures in the resources.
They are also known as an Ethical Hacker or a Penetration Tester. They focus on Securing and Protecting IT Systems.

Black Hat Hacker:- A Black Hat Hacker is computer guy who performs Unethical Hacking. These are the Criminal Hackers or Crackers who use their skills and knowledge for illegal or malicious purposes. They break into or otherwise violate the system integrity of remote machines, with malicious intent.
These are also known as an Unethical Hacker or a Security Cracker. They focus on Security Cracking and Data stealing.

Grey Hat Hacker:- A Grey Hat Hacker is a Computer guy who sometimes acts legally, sometimes in good will, and sometimes not.
They usually do not hack for personal gain or have malicious intentions, but may or may not occasionally commit crimes during the course of their technological exploits.
They are hybrid between White Hat and Black Hat Hackers.

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