What is the difference between a search engine and a directory?
Search engines are tools that search for information in databases built by computer programs called web crawlers, spiders, or robots. The search results are usually presented in a list. Directories are usually human edited. Directory indexes are built by editors who visit websites and add any they determine to be a valuable resource. Directories list websites by categories and subcategories.
Many search engines work through automated web browsers, known as crawlers or spiders. Spiders read your site’s source code in order to try to categorize the information on your site and find any relevant keywords and phrases. Search engines like Google measure the importance and weight of incoming links to your page, in addition to other factors. These factors and your site’s content combine to create your web site’s ranking or relevance, known as PageRank on Google. Directories are hand maintained sites that attempt to manually categorize websites. An example would be the Open Directory Project or Yahoo’s Paid Directory. Directories are usually slower to update because they are generally maintained by humans. However, since they are maintained by humans, they are generally more accurate and harder to game or spam than a search engine would be.
A search engine indexes Web sites by sending “spiders” or “crawlers” to your Web site to review it’s coding and content for relevancy. These computer programs read the coding of the Web site and determine it’s ranking according to how the coding, content, and links match up with their algorithm. Directories, on the other hand, have real people review your Web site for relevancy. They look at the overall site from a human point of view. They still have algorithms they use to help rank a site, but the human factor is also involved. In addition, you must submit your Web site to a particular category set up within the directory. Understanding the most appropriate category and what the editors will accept or reject for titles and descriptions is very important. Once you are entered into a directory category with a title and description, it is very difficult to ever get it changed. Make sure it’s done correctly the first time!
The fundamental difference between search engines and directories is that search engines utilize spiders/crawlers to gather information about websites (e.g. Google), whereas directories are usually human edited and require a human to input this information during the submission process (e.g. Directory Registration).
Search Engines are similar to a library catalog index. Each search engine categorizes and searches websites based on keyword or concept. Small programs called algorithms do all this, so it’s easy to fool them…if you know how. Some companies will tell you they can easily get your website in the top ten by manipulating the search engine ranking programs. But it isn’t worth cheating. If the search engines find out you are cheating they will ban your website, usually for all time. Once you get kicked out of a search engine, it’s extremely difficult to get listed again. And other search engines are told too, so you could end up being banned from a large majority of search engines. Honesty is the best policy.
