There are several types of hackers: White hat hackers test security systems legally as ethical hackers; Black hat hackers illegally access systems to harm them or steal information; Grey hat hackers exploit systems without permission but to expose vulnerabilities; Red hat hackers target sensitive government or secret information; Blue hat hackers test systems on behalf of companies; Elite hackers are highly skilled; Script kiddies use pre-made hacking tools without understanding; Neophytes are new to hacking; and Hacktivists hack to spread a message while Phreakers target telephone systems.