White hat hackers
They are also known as ethical hackers. They are those hackers who use their knowledge to find vulnerabilities in a computer system and bring it to the attention of development companies or companies, with the aim of being able to study and correct the failures. They seek to improve security systems, whether through security in applications, operating systems and protection of sensitive data, in order to guarantee the confidentiality of user information.
In this type of hacker, we can find both security researchers and those who hack systems for non-malicious reasons to demonstrate to a client or a company they work for that the computer system is not secure. There are certifications, courses, and online training that cover the entire sphere of an ethical hacker
Black hat hackers
Also known as crackers, they are really the criminal hackers that cause all the cyberattacks that do not stop appearing in the press. He is a hacker who uses all his knowledge to enter systems like white hackers but in a malicious way, looking for his personal/economic benefit. They are responsible for all the spam we receive in the mail, the ones that make malware viruses, the ones that sneak into the systems of large companies to modify or destroy data, steal information from users and then sell it to the highest bidder, collapse the system, and a long etcetera.
Grey hat hackers
Among the white and black hackers, we find the grey ones (it sounds like a joke but it’s not). This is the name given to hackers who break the security levels of a company’s systems to subsequently offer their services to improve said security. That is, they attack the computer system of a company to demonstrate its value, and be hired to defend it by fixing its security flaws.
Here we could be talking about anonymous individuals expressly hired, or grey hackers who go freelance and after hacking a system or company, offer their services. An example would be the hackers hired by some governments to spy on other countries.