Primary structures of the Internet are directories. It is not surprising, because in the early development of the Internet to find the appropriate link to your site has only been possible in the directory. The value of this structures decreased with the advent of search engines such as "Yandex", "Rambler," "Google" and others – find information on the Internet has become automatic. But now we can not deny the benefit of the directories for the sites in the development of or having a low rating so far. Moreover – in a directory of articles it is possible to find even a link to the site, completely unknown.

Search for articles in the online catalog is simple: they are usually located on the headings, in accordance with the subject. Nevertheless, it is possible to find the same article attached to the various headings. These catalogs are available for any visitor to the network and their basic function – to inform, because kataloah collected an incredible amount of interesting and important articles, which include a link to the website source. The catalog is, of course, and that each user can, if desired, to catalog own article of any subject. The unit directory is thematically: that is, there is a directory devoted exclusively to a particular topic (eg, construction or engineering), and catalogs obschetematicheskie, which is information on every conceivable topic. Also, the article directories is possible to divide into three so-called "color" of the group.

"White" directories do not require registering a back reference. But if the webmaster who publishes your article, yet to make white catalog link, the page describing his site will get ranked higher in comparison with a standard reference. Thus, to link to catalog all the same profitable. Gray directories require a link back to the unfailing order, and place a link to before, to apply for their placement of the article. And finally, the directories are black – they set the link announced on site instead of only reciprocal links directory that you are using.