Search engines and the directories are two different services available to the Web community. However, many people do not know the difference between them. Search engines have databases built up by "robots", which visit a websites and add information to their database. On the other hand, directories are human edited and build their indexes with editors who visit websites, and add to the directory the sites that they consider to be a valuable resource.
Some search engines and directories include both types of indexes, and are known as "hybrids". Some examples of search engines are Google, Gigablast, and Alltheweb. These search engines use programs (known as robots), with the following functions:
1. To find web pages.
2. To scan the contents of a web page.
3. Return its findings to the search engine's databases.
Most search engines update their databases frequently. When web searchers use a search engine to locate websites relevant to the keyword (or key phrases) searched, they are searching the search engine's database. Therefore, a search engine with a frequently updated database should provide better search results.
The best known directories are Yahoo, Business.com, Dmoz.org, and Looksmart. These directories employ human editors to review websites that are submitted for possible inclusion into their directory. The directories usually include only the main page of a website, while search engines can include many pages from a website. The process of adding sites to a directory manually is much slower than the automated work of robots. Therefore, most of the time there are many more websites indexed by a search engine than in a directory. However, the directories have an advantage: The data organization.
Directories, unlike search engines, use a tree hierarchic structure to organize their database. This hierarchic organization allows the existence of specialized directories, by subject or by geographic location. One example is Checkhouston.com, a directory dedicated specifically for information and businesses in the area of Houston, Texas.
You may wonder how these services make money, as they are free for the user.
There are several sources of income:
1. Directories generally charge a fee for websites interested
in being added to their database. This fee is to cover the costs
of the human editors reviewing the site, and other directory
expenses. There are exceptions such as joeant.com, webbeacon.com and dmoz.org,
whose editors are volunteers working for free.
2. Search engines show sponsored links, in addition to the natural result. These advertisements are very effective for two reasons: a) The advertisers’ website is highly relevant to the user search, and b) the advertiser only pays for the users who click in their ad.
3. There are "pay per click" search engines, in which all the results are paid placements. In these search engines, the first search result is the advertiser bidding higher for each search term they are targeting. Although some may think that the results of these searches would not be very useful, actually, most of the ads are professional sites, willing to pay to attract possible customers. The best known "pay per click" search engine is Overture.
What is better, a search engine or a directory? It depends on what are you looking for. If you are looking for information quickly, a search engine might be better. But if you like browsing categories or looking for industry specific information; a directory can be a better option. A directory dedicated to a specific geographic location is an excellent tool to find products and services in your locality.
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