Black hat search engine optimisation does not take into account the guidelines of Google. SEO techniques that are not permitted by Google are used. As a result, you run the risk of a penalty from Google, which means that your website or page can be removed from the search results. The opposite of black hat SEO is white hat SEO. In white hat SEO, you follow the guidelines of Google.
Black hat SEO often involves the use of techniques that used to be permitted, but are no longer used. For example, hiding content from the visitor, while the crawler can see it. Or the use of keyword stuffing. In this case, black hat SEO is deliberately used to achieve quick results and a higher score in the search results.
In addition, black hat SEO is used for research purposes. By conducting research in the field of black hat SEO, we are increasingly aware of what does and does not work. We test which techniques lead to which results and which penalties Google gives to certain actions. This knowledge is therefore very useful to make a website SEO-proof.