A web directory is just what it sounds like: a directory that is found on the World Wide Web, that directs you to various web sites. Unlike a search engine, which displays results based on key words and phrases, a web directory groups information into categories by topic. Perhaps the best known web directory is the Yahoo Directory.

Directories organize info that can be accessed in a process known as "drilling down"-you go from the most general (for example, "travel") to increasingly specific subcategories (for example, "United States," "amusement parks"). You might drill down from "Reference" to "Phone Numbers" to "Businesses" to get to a listing of various online yellow pages.

A web directory directs you to links to web sites that may contain the information you seek. Insiders refer to directories as either general or niche. Niche directories attempt to collect as much information as possible within specific research areas, for example, a web directory of career advice, or a web directory of safe toys for children.

A web directory can take different forms, according to how the information is gathered. Some directories accept paid submissions. Information is there because people pay to be listed. Sometimes listings are free but the positions are paid for. Understanding the structure of how a web directory collects and presents its information lets you now how much you can trust the information it contains.

Directories can be a part of many an online business's search engine optimization strategy. The more diverse the links pointing to a specific web site are, the greater the chance for better traffic, and the higher the possibility of ranking in search engine algorithms. Paying to be listed in more than one directory, or to be found quickly through premium positions in a directory, can result in improved traffic to the listed web site.