The search engines are some specialized sites that quickly find Web pages which contain the search terms specified by the Internet users who use their services. They have a very simple operating principle, which is based on using a special program called “robot crawlers” (dragged robot) who regularly visit Web pages throughout the Internet.
The dragged robot collects from each visited Website some data that is stored in the database of the search engine. This process is called indexing Web pages and is repeated every time a page is visited, to highlight any changes and update the database. When the Internet users search for a Website containing a specific word (or a certain phrase), the search engine addresses to its database and makes up an ordered list of those Websites.
In this list is presented every page with: the HTML title (in the form of hyperlinks to the Web page address), an extract from page to prove the presence of the searched words and the Web page address.
The composition of the list with pages that contain a certain word is a very complex process because it involves sorting pages by their relevance. The relevance of a page is defined as a measure of the quality of information on that page, with referrence to a particular word or phrase. Let’s suppose we want to create a Website, thus we want to find the Website of a company specialized in Web design or a site that presents Web tutorials, if we want to create our own site by ourselves.
Now I have introuduced the term “Web design services” and you have to do the same if you want to obtain some results using a search engines. So, write what I have written before, but without quotes in the text box of a search engine and wait for the result. The search engine will investigate its database with pages containing those words and will provide a list of, let’s say, five hundred Web addresses. If the pages would not be sorted by their relevance, you would have to visit as many of them and this would be very difficult, even if the search engine helps you by providing you the title of the page with its address.
Some search engines use specialized algorithms to sort Websites according to their relevance. These algorithms are not infallible, but they often do not fail to rank the pages in such a way that those which contain the best information are on top of the list. In short, an algorithm must place a Web page that contains technical details about the creation of a Website or a Website design firm specialized in creating Web pages before an online forum which contains the following phrase: “I want to set up a Web services business “.
All three pages contain the search phrase but the page from where I extracted the quotation has no relevance if you find a company that creates Web pages or we want to know technical details that could help us to achieve the desired site by ourselves.
The algorithms used by a particular search engine are different from those of other engines and are secret because they determine the success, thus the economic viability. The more the Websites list is better sorted (in such a way that pages with high relevance are present at the top of the list) the more a search engine will be used by Internet users and will be able to sell more advertising.
The algorithms are constantly developed and improved by teams of programmers and linguists specialized in statistics to mathematicians. Although the algorithms are secret, the specialists in optimizing Web pages have managed to highlight some features that make the Web pages to have a great relevance in the “eyes” of the search engines and therefore they are placed on top of the list generated by them.
However, quite a few of these features are still subject of debate among specialists about their importance when the algorithm decides the place of a page in the list. There is a great number of search engines, but the Internet users use only two or three of them. In fact, the most frequently used search engine is Google, with approximately 90% of the Internet search.
This approach of seeking information on the Internet is not always the most effective, but many Internet users prefer to use one search engine for reasons of convenience and because Google usually gives lists of top pages that are filled with relevant pages. It is recommended to use at least two engines when looking for something on the Internet. A good search engine is MSN which gives results as good and sometimes better than Google.
Obviously there are situations where the results offered by Google are better than those offered by MSN and it is therefore better to use both. Another recommended search engine is Yahoo.
The search engines are divided into three categories:
Engines which have their own database (Google and AllTheWeb)
Engines that use the databases of other engines (MSN uses Inktomi and LookSmart services)
Engines that use both their own database as well as those of other engines (Yahoo is using its own database but also that of Google, Inktomi (which they bought) and Overture (which they bought also).
There is also a special category of sites that cannot be called search engines in the true sense of the word but who can prove their usefulness. These are so-called integrative engines (clustering engines or metasearch engines) and are represented among others by ProFusion, Vivisimo and Dogpile. If you enter the text box on these sites a word or phrase, the search will be triggered by at least five engines (Google, Overture, MSN, AllTheWeb, Altavista) and the obtained list will be sorted by the integrative engine and then presented to us. These engines give good results and their use is recommended.11