Search Engines and Directories
People often use search engines and directories synonymously as expressions to search anything on the Web. However, the two are quite different and an understanding of the differences will help you promote your site successfully.
Search Engines
A search engine uses highly sophisticated software to search the web for new pages. This program is popularly known as “spider”. It then automatically creates and updates their indexes, thereby building databases. Web documents are retrieved by these programs and analyzed. The spider will return periodically to the pages and check for updated content. Whenever it finds an active hyperlink, it will follow it and add that to the index and so on. When you enter a query at a search engine site, your input is checked against the analyzed web pages in the index created by the search engine. The best URLs are then returned to you as hits ranked in order with the best at the top.
Directories
The main difference between a search engine and a search directory is that the latter is compiled by a real person. Another difference is that while a search engine can list every page in your website, a directory will contain only a single entry covering your website.
Directories are categorized so that it is easy to find what you are looking for. The site owner may issue a brief description of the site along with its URL to the complier so that it can be considered for inclusion.
When you submit your site to a directory, you select the suitable category for your site. A reviewer then checks to ensure that your site is in the most appropriate category.