There are search engines that finally bring your website to the attention of prospective customers. Therefore it is better to know how these search engines work and how they present information to the customer initiating a search.
There are essentially two types of search engines. The first is by robots called crawlers or spiders.
Spiders of search engines use to index websites. When you submit your website pages to a search engine by completing their required submission page, the search engine spiders index your entire site. A “spider” is an automated program that is managed by the search engine system. Spider visits a web site, read the content on the site, the site of the Meta tags and also follow the links that the site connects. The spider then returns all that information to a central depository, where data is indexed. He visits each link you have on your website and index those sites as well. Some spiders only index a certain number of pages on your site, not to create a site with 500 pages!
Spider back periodically check the sites for any information that has changed. The frequency with which this occurs is determined by the moderators of the search engine.
A spider is almost like a book where it contains the table of contents, content and links and references to all the sites it finds during its search, and the index can make more than a million pages per day.
Example: Excite, Lycos, AltaVista and Google.
When you ask a search engine to find information, it is actually searching through the index that he created and not actually searching the Web. Different search engines produce different rankings because not every search engine uses the same algorithm to search through the indices.
One of the things that the algorithm of a search engine scans for is the frequency and location of keywords on a Web page, but it can also detect Keyword stuffing or artificial spamdexing. Then the algorithms analyze the way the pages of links to other pages within the site. By checking how pages link to each other, an engine can both determine what is around a page, if the keywords of the linked pages are similar to keywords on the page ‘ origin.