The dark Net is a collection of all websites and their links that are hidden from the traditional web; they make money this way. These links are also known as links that are not included in the "known" directories and are only accessible through the secretive "underground" networks. Some of these links to make money are so common that the search engines will list them as a website associated with spam or as being part of an illegal site. However, many legitimate websites use these links for promoting their business and are listed by search engines, because they are relevant.