The hacker is a person who is involved in security / insecurity and is particularly skilled at finding vulnerable aspects of the security system, or is capable of illegal intrusion into other computer systems or possessing deep knowledge about it.
In general, the term hacker is more commonly used in the sense of black hat hackers who carry out basically destructive and criminal acts. There is also a moral hacker and an immature hacker about morality.

To distinguish between these, the term 'craw' is often used to distinguish hackers from academic security or academic hackers, or to distinguish moral hackers from dishonest hackers.