A web directory or link directory is a directory on the World Wide Web. It specializes in linking to other web sites and categorizing those links.
A web directory is not a search engine and does not display lists of web pages based on keywords; instead, it lists web sites by category and subcategory. Most web directory entries are also not found by web crawlers but by humans. The categorization is usually based on the whole web site rather than one page or a set of keywords, and sites are often limited to inclusion in only a few categories. Web directories often allow site owners to submit their site for inclusion, and have editors review submissions for fitness. – http://en.wikipedia.org/wiki/Web_directory
Directory entries are often mentioned as another way to promote young sites in the Google index. There are great, topical directories that add value to the Internet. But there are not many of them in proportion to those of lower quality. If you decide to submit your site to a directory, make sure it’s on topic, moderated, and well structured. Mass submissions, which are sometimes offered as a quick work-around SEO method, are mostly useless and not likely to serve your purposes.
Free fast approval directory submission list