Yahoo! Directory is the first and original categorizing web directory on the internet. Yahoo started as a simple website to help organize the new links on the internet, and has since turned into a multi-billion dollar corporation. While the directory still is one of the most trusted, human-edited directories on the internet, Yahoo's primary business is its search engine and the advertising surrounding it. A Yahoo! directory listing is free for most non-commercial websites, however an annual editorial fee is required to be listed in most cases.