Yahoo! is an Internet portal that incorporates a search engine and a directory of World Wide Web sites organized in a hierarchy of topic categories. As a directory, it provides both new and seasoned Web users the reassurance of a structured view of hundreds of thousands of Web sites and millions of Web pages. It also provides one of the best ways to search the Web for a given topic. Since Yahoo is associated with the most popular Web search sites, if a search argument doesn't lead to a Yahoo topic page, it will still lead to results from the six or seven popular search engine sites Yahoo links to.
Yahoo! began as the bookmark lists of two Stanford University graduate students, David Filo and Jerry Yang. After putting their combined bookmark lists organized by categories on a college site, the list began to grow into an Internet phenomenon. It became the first such directory with a large following. Filo and Yang postponed their graduate work and became part of a public offering for a multimillion dollar corporation. As of October, 2005, Yahoo was serving approximately 3.4 billion page views worldwide.
According to the site's official FAQ (frequently asked questions) list, Yahoo stands for "Yet Another Hierarchical Officious Oracle.