Hacking refers to the act of gaining unauthorized access to computer systems, networks, or digital devices with the intent to modify, manipulate, or extract information, or to disrupt the normal functioning of the target system. Individuals who engage in hacking are known as hackers.

Hacking can be broadly categorized into two types:

1. Ethical Hacking (White Hat Hacking): Ethical hacking involves legally and with proper authorization, attempting to identify security vulnerabilities in computer systems, networks, or applications. Ethical hackers, also known as "white hat" hackers, use their skills to improve cybersecurity by finding and fixing weaknesses before malicious hackers can exploit them. They often work as cybersecurity professionals, penetration testers, or consultants.
2. Malicious Hacking (Black Hat Hacking): Malicious hacking involves unauthorized and illegal activities carried out with malicious intent. Malicious hackers, also known as "black hat" hackers, exploit security vulnerabilities to gain unauthorized access, steal sensitive information, disrupt services, or cause harm to computer systems, networks, or users. These activities are illegal and can result in severe legal consequences.

There are also "gray hat" hackers who do not have explicit malicious intent but may engage in hacking without proper authorization. They may discover and disclose vulnerabilities without malicious intent, but their actions are still considered illegal and unethical without proper authorization.