A SEARCH ENGINE is a website that interfaces with a giant database of websites that have been indexed. Usually, a program known as a "crawler" accesses every page of your website, aside from any pages hidden from automatic crawlers (specified by your webmaster in a file on your website).

Every search engine uses a slightly different method to index each link. For instance, Excite.com uses advanced linear algebra methods to reduce each link to a vector. Whenever users create a search on the site, Excite reduces the search to another vector. Then, the search engine compares the search vector to the vectors in the index. The vectors of the websites that most closely correspond to the search vector are returned as results. And the relevancy percentage is simply the measurement of the angle between the two vectors!

Google (www.google.com) is another search engine with a different indexing method. Google uses a search algorithm known as PageRank, which uses the number of pages which link to a site as an indicator of an individual page's value. Each page is also automatically examined for content to determine whether the page is likely to match with your search.

To learn more about search engines and how they work, an excellent guide is available at http://www.searchenginewatch.com/webmasters/index.html.

In order to submit your site to a search engine, you must simply add your URL to the crawler's list of websites to look at. This makes submitting information to a search engine very easy. However, submitting information to a search engine will not help people find your site through that search engine unless your website is appropriately designed. For more information about designing websites for search engines, go to http://www.northernwebs.com/set/. Northernwebs is one of many, many guides to search engine submission techniques, but it is a very good summary of the most commonly pointed out techniques.

A DIRECTORY is a website that contains lists of websites organized by category. Generally, directories have NOT indexed all the words on the website.

Directories are manually created. Usually, directories require you to pick categories and enter a short description when you are submitting your URL. A human then typically screens your submissions to make sure the categories and descriptions are appropriate. Yahoo! is a good example of a web site that is primarily a directory. Notice that many (if not all) directories now also have searching capabilities, often outsourced to a search engine.

Submitting information to a directory can often be more valuable than to a search engine, but only if the directory is specifically targeted to what you do. That is, a local directory to help people in your area find your site, or an industry-specific directory are much more likely to bring you significant traffic than a search engine. That is not to say that registering with the top ten or fifteen search engine sites is not a good idea, especially given how little effort the search engine submission process is. You will receive some traffic, particularly from those visitors specifically searching for your site.