A web directory is a listing of websites on the World Wide Web. Its major function is to provide access to other websites through a directory of links which are categorized under certain subjects of interest. The categories are then further divided into many sub-categories to narrow down the possibilities.

Web directories are often confused with search engines, but they are different in one or two aspects. First of all, a web directory is put together by human reviewers whereas a search engine is compiled by automated systems. If you wish to have your website included in a web directory, you are required to submit your site for review, which is done by a group of human editors.

Also, in a web directory, websites are displayed according to their relevant categories or sub-categories while a search engine uses keywords to locate the sites related to the search. In this sense, the links found in a web directory are representations of websites in their entirety, not the single page results of a search engine. The common misconception concerning web directories and search engines is due to the emergence of some hybrid search engines which include certain features characteristic of web directories, such as categorization and site quality.

There are many web directories available on the Internet today where some are more general and extensive in their categorization than others. The most popular web directories are Yahoo! Directory and Open Directory Project (ODP). ODP is considered the premier web directory because of the large number of websites represented there. Other directories and search engines can also access ODP for free, and this has led to violations of use where content in ODP is used without acknowledgement.

Depending on the price paid upon submission, different kinds of listings can be arranged. For common submissions, there are free and paid submissions as sites are submitted for reviews, while other submissions include reciprocal link, no follow, featured homepage link and featured link. For a reciprocal link, a website has to link back to the web directory as a requirement to get listed. A no follow is the attachment of a "no follow" tag to a certain website with the purpose of deterring search engines from following. As a featured homepage link, a site will be featured on the homepage of the directory while featured link place the site in a premium position.

Web directories are some Internet users preferred way of finding links. However, compared to search engines, web directories are not precise enough in locating specific information on the Internet. Those who use search engines can be directed to a particular page in a website which displays the exact information they are looking for. Since web directories only lead to websites, there is still some searching to be done before the desired information can be reached. It is can be quite a cause of inconvenience.

However, in terms of accuracy in interpreting the search terms, web directories do not display so many irrelevant possibilities as search engines. In general, a web directory is still a better way to search because it is compiled by humans for humans.