White Hat Hacker
Definition - What does White Hat Hacker mean?
A white hat hacker is a computer security specialist who breaks into protected systems and networks to test and asses their security. White hat hackers use their skills to improve security by exposing vulnerabilities before malicious hackers (known as black hat hackers) can detect and exploit them. Although the methods used are similar, if not identical, to those employed by malicious hackers, white hat hackers have permission to employ them against the organization that has hired them.
Techopedia explains White Hat Hacker
White hat hackers are usually seen as hackers who use their skills to benefit society. They may be reformed black hat hackers or they may simply be well-versed in the methods and techniques used by hackers. An organization can hire these consultants to do tests and implement best practices that make them less vulnerable to malicious hacking attempts in the future.
For the most part, the term is synonymous with "ethical hacker." The term comes from old Western movies where the cliché was for the "good guy" to wear a white cowboy hat. Of course, the "bad guys" always seemed to wear a black hat.