An article directory is like a "yellow pages".
Keep in mind that not all directories work the same way and posting your links may be considered to be duplicate. Read further once you choose which directories to use before you post on them.
"An article directory is a website with collections of articles written about different subjects. Sometimes article directories are referred to as content farms, which are websites created to produce mass content, where some are based on churnalism.
An article directory may accept new articles from any contributor, but may require that a new article is unique (not published elsewhere) and not spun (see article spinning). A typical article is around 400-500 words, and tools such as a WYSIWYG editor for writing and submitting an article may be provided."Wikipedia