Search Engines Vs. Directories: What's the Difference?
Customer Support Documentation, PlacerWeb, 1999
You've probably heard that your website must be found in the SEARCH ENGINES in order to get hits (visitors) on your website.
This is because the most common way that Web surfers find things is by SEARCHING. Most web surfers know WHAT they want, but they don't know the exact address of a website that has what they want. So they go to a website that offers the ability to SEARCH.
There are two major kinds of search websites: search engines and directories.
A SEARCH ENGINE is a website that interfaces with a giant database of websites that have been indexed (usually every word on those websites have been indexed in the database).
When you search, the search engine shows you a list of websites that contain the word or phrase you're looking for (commonly called a "search term" or "keyword"). The websites that appear to be most relevant are listed first. Search engines determine "relevance" by various formulas, usually involving how many times your search term shows up in the page and whether the search term shows up in prominent places like the page title. The more relevant a website seems to be, the higher up on the list it will be displayed.
You can get your website listed in a search engine by going to the search engine's "website submission" page and telling the search engine that your website exists by "submitting your URL".
This just means that you give the search engine the ADDRESS of your website (http://www.yourcompany.com) and you ask it to index that website in its database.
When the search engine gets around to it, then it will index your website and add it to its database. Then, when people search for a word or phrase (a keyword) that is on your website, your page will show up somewhere in the results.
Whether or not you're toward the top of the list is determined by how many other websites are in the database that also contain that keyword, and whether the search engine's relevance formula thinks that your website has more relevance than the other websites.
Some search engines will list your website within days of when you submit the URL, others take months and many re-submissions.
For more (complete and updated) information about how various search engines work, see the Search Engine Watch website.
A DIRECTORY is a website that contains lists of websites organized by category. Generally, directories have NOT indexed all the words on the website.
Instead, the websites are listed in the categories where they belong with a title and short description to guide people. Yahoo.com is the most popular directory on the Web and is the classic example of a directory.
It usually takes longer to get into directories because they will generally have a real human being review your request before putting your website into the categories you've requested (they want to make sure that your website really belongs in those categories). So getting into Yahoo might take 2-6 months, with re-submissions every 4-6 weeks.