The working principle of the search engine

Wiki definition

SEO is the abbreviation of Search Engine optimization, described in English is touse some technics to made your website in the top places in Search Engine wh En somebody is the using search Engine to find something, translated into Chinese is "search engine optimization", generally referred to as search optimization.

It is very difficult to define the search engine next. 1000 people have 1000 search engines: Some think the search engine is Baidu, some people think that the search engine is Google, some people think that the search engine is Yahoo. If you want to give a definition, let's take a look at how the Microsoft Encyclopedia (MSN Encarta) defines search engines:

SEO's main work is by understanding how various search engines crawl Internet pages, how to index and how to determine their ranking of a particular keyword search results, and other technologies to optimize the Web page, so that it can improve search engine rankings, so as to improve the number of site visits, The technology that ultimately promotes the site's ability to sell or advertise.

Search Engine,,software Program This helps users find information stored on a personal computer,or a network of computers, such as the Internet. A user enters search terms,typically by typing a keyword or phrase,and the search engine retrieves a list of world Wide We B (WWW) sites,personal computer files,or documents, either by scanning of the content stored on the computers or computer net Works being searched or by parsing (analyzing) a index of their stored data.

The basic working principle of search engine

The number of Web pages currently on the Internet is China, and these sites are stored on different servers and distributed around the world in data centers and computer rooms.

For search engines, it is almost impossible to crawl all the pages on the Internet, and from the current data, the largest search engine is just crawling around 40% of the total number of pages. On the one hand, there is a bottleneck in the crawl technology, unable to traverse all the pages, there are many pages can not be found from the links of other pages, another reason is the storage technology and processing technology, if the average size of each page 20K calculation (including pictures), 10 billion web page capacity is 2000G bytes, Even if it can be stored, there are problems downloading (according to a machine download 20K per second calculation, requires 340 machines non-stop download a year to download all the pages). At the same time, because the amount of data is too large, in the provision of search will also have an efficient impact. Therefore, many search engine web spiders just crawl those important pages, and evaluation of the importance of the main basis is the link depth of a page.

In fact, search engines will visit a large number of sites in advance and store some of the information on their servers beforehand, so that when users search, it is in the search engine's own server to query, as we do in our own computer query files.

Search engines are very complex technologies, but their basic sort.

Some people think that the search engine receives the search request, will be in real-time from all the global Server query information, and the query results displayed in front of the user, this is actually a misunderstanding. If the search engine works this way, it may take several years to query for a message, which does not include changes in the duration of the page.

A search engine is a program that helps users find information stored in a personal computer, computer network, such as the Internet. User input search items, usually by typing a keyword or phrase, the search engine returns a list of World Wide Web sites, personal computer files, or documents by describing the computer and computer network being searched, or by decomposing (analyzing) the index of their data.

Some explanations at home

Search Engine optimization is one of the common forms of search engine marketing. The so-called search engine optimization, that is, for a variety of search engine retrieval features, so that web design suitable for search engine retrieval principles (that is, search engine friendly), so that the search engine included and in the rankings in front of all kinds of behavior. For search engines based on META tag search, set up effective keywords and site descriptions in meta tags, for Spider-Type search engines with Web content dependencies, add the keyword density to the Web page, or design a page that is easy to retrieve for search engines ( such as sitemap.htm, Roberts.txt).

So far, the definition of more authoritative is: Search engine optimization, refers to follow search engine search principle, the website structure, Web language and interactive diplomatic strategy between the site planning and deployment, to improve the site in search engine performance, thereby increasing the possibility of customer discovery and access to the site of such a process. Search engine optimization is also a scientific development concept and methodology, it develops with the development of the search engine, but also promotes the development of the search engine.

Robin based on its search engine optimization for more than two years to summarize the search engine optimization definition: Search engine optimization is such a technology, that is, follow the search engine science and comprehensive theoretical mechanism of the site structure, Web language and the interactive diplomacy between the site planning and deployment to explore the greatest potential of the site to make it in the search engine has a strong natural ranking competitive advantage, so as to promote enterprise online sales and strengthen network brand play a role.

First, crawl

The search engine will first send out a software called "spider" or "robot" that exists on the Internet, along with links from one Web page to another, from one Web site to another Web site. In order to ensure the latest collection of information, it will also visit the Web page has been crawled.

Second, index

Analysis of the collected pages by the Analysis Index System program, extracts relevant web page information (including URL, encoding type, page content contains all keywords, keyword location, generation time, size, links to other pages, etc.), according to a certain degree of correlation algorithm for a large number of complex calculations, Get the relevance (or importance) of each keyword in the page text and in the hyperlink, and then use the relevant information to build a Web page index database.

Third, sorting

When the user enters a keyword search, the search system program from the Web page index database to find all the relevant Web pages that match the keyword. Because all relevant web pages for the relevance of the keyword has already been good, so just according to the availability of the relevance of the ranking, the higher the correlation, the ranking the more forward.

Finally, the search results are organized by the searcher and returned to the user by the link address and the content summary of the page.