modern search engine - is a complex consisting of complex programs and algorithms working with mind-boggling speed.Just imagine new Caffeine search algorithm from Google is able to process information, the equivalent of 3 km A4 sheets, in just 1 second!
all search engines software components can be divided into five main groups:
- «traveling spiders»
- system SERPs
Program spiders - spiders (spiders) - the algorithm of its work resemble browsers, but do not have any visual components.Spider loads the html-code of the page, using the protocol http.
Request robot server includes a command «get / path / document» and some other teams http-request.This request from the server to the spider gets a response in a text stream, comprising overhead information about the document and the document
«Traveling spider» - crawler - represents another component of the indexing module.Crawler automatically enters all the hyperlinks that have been found spidering the page and thus searches for the search engine is still unknown documents.
robot indexer (indexer) works directly with the content of the pages you spidering.The indexer spends morphological, lexical analysis pages, breaking them down into separate parts.
Databases (database) is a special software for the storage of collected and pronalizovannyh document indexing module components.
Search engine results engine - the system of delivery of results - one of the most important components of a search engine.It is the system of delivery of results is concerned the end user who enters a query into the search box.The system of delivery of results on the basis of more than two hundred different selection criteria are met results most satisfying search target.
this selection algorithm is usually called an algorithm or mechanism ranking .In order to avoid manipulation by webmasters to influence the results of the issuance, the exact ranking algorithm the search engines are kept in the strictest confidence.
Nevertheless, there are a number of known criteria to be considered when using the search engine optimizing that a webmaster can "legally" to influence the results.For example, search engine takes into account when analyzing the page :
- whether there is a keyword in the page title (Title)
- whether there is a keyword in the URL of the page
- whether there is a keyword in titles H1-H6, tags STRONG,B, EM, I
- what keyword density on a page (Density)
- whether there is a keyword in the meta-tags: keywords, description
- present there on the page internal and external links
user interaction with the search engine is carried outthrough a search engine. resulting from a user search request, the server processes and transmits as input module ranking.In turn, the unit carries out the processing of documents for which information is stored in the database search engine and ranks the pages corresponding to the user's request.
The system then generates a snippet - text information, which is displayed to the user in a SERP (Search Engine Result Page) - page of search results .
Thus, even a brief description of the basic principles of search engines shows how closely interlinked with each other all of the software components of the system and how clear and perfect a search engine has to work in order to quickly and reliably provide the user with information on his search query.