Final answer:
Black hat hackers are those who unlawfully infiltrate computer systems, often using deceptive practices to exploit vulnerabilities and obtain sensitive information.
Step-by-step explanation:
Black hat hackers are the "bad guys" who attempt to gain unauthorized access to computer systems. These individuals can use a variety of methods to breach systems, such as finding vulnerabilities to exploit in websites, enticing people to click on malicious links, or tricking users into providing sensitive information. In contrast, white hat hackers are ethical security professionals who help protect systems, and gray hat hackers operate in a more ambiguous space, sometimes violating laws but without malicious intent. Red hat hackers, although less commonly mentioned, are typically involved in targeting black hat hackers to stop their activities.