A white hat may refer to any of the following:
1. An ethical hacker who attempts to find vulnerabilities in computer and network systems; a white hat identifies security weaknesses then informs the appropriate personnel. These individuals are employed by companies and governments, usually to protect the organization's information systems.
2. When referring to an SEO, a white hat SEO is someone who follows all of the rules and guidelines of a popular search like Google when promoting a website. A white hat SEO does not participate in any bad SEO tactics like a black hat SEO.