These are manually created sites that catalog information in categories. Yahoo and Magellan are examples of directories on the Internet. When you use one of these search sites it will take you to a general category, then allow you to select sub-categories. Let's say you are looking for sites about football. Pick the one you want and you move to that Web site.
Directories quickly find targeted information on general topics.
Think of the people that work for these directories as editors. They select the content. The second type of service you'll find are the search engines. The engines use robots or spiders to crawl through the Web, collecting information. That information goes into a database that your customers call up when they are looking for a service or goods you may provide.