How does a search engine work?

Internet users around the world use search engines to obtain information. Indeed, billions of information are put on line, then modified daily by the persons in charge of the sites. Search engines are software programs that sort the information sought according to the keywords entered by Internet users during their searches. So, how do search engines work on the Internet?

How does a search engine work in general?

A search engine is a software that allows you to search the internet.

A search engine works with the help of robots called crawlers

When an Internet user searches the Internet, he or she must use a search engine. The user will then have to insert keywords so that the search engine can display relevant results related to the requested information. Once the keywords are inserted, the search engine will scan all the sites containing the requested information. To find relevant results, the search engine relies on robots to sort and analyze sites that are compatible with the requested information. To do this, the robots rely on precise criteria to be able to sort the websites, find those that are of quality and display the results.

A search engine relies on complex algorithms

Complex algorithms are combined with a search engine to identify the nature of the information or documents published on the Internet, such as photos, music, videos… Of course, a search engine’s objective is to quickly provide results with relevant content to the queries made by Internet users. The algorithms will therefore both interpret the terms searched for by Internet users and momentarily display the results with valuable content.

A regular update of the algorithms

In order to ensure that the results of the websites displayed are always the best, the algorithms built into the search engine must be updated frequently. With the ever-increasing number of documents uploaded daily, the relevance indicators are also strengthened. Website owners must then be up to date on the new criteria so that their site pages are always at the top of the list of results displayed.

What steps do search engines take to display results to users?

In order to display the results requested by a user, search engines proceed in two steps: crawling and indexing.

The crawling

This is the first step a search engine takes when performing a search. Crawling consists of systematically inspecting the pages of websites. The search engine will gather all the information present on the different online platforms. This feat is accomplished by crawlers or spiders (the robots that help the engines to perform searches). Once the information is gathered, the crawlers send it to the index so that the search engine can perform the indexing.


When the engine brain or index receives the information gathered by the crawlers, it proceeds to indexing. This step consists of evaluating all the sites gathered, then organizing and ranking them according to the valuable content of each of them. Once this evaluation is complete, the search engine can display results according to the quality of the content of each site.

How does a search engine define the ranking of an online site?

Google search engine on a laptop

A search engine uses robots to analyze each site associated with the terms searched by a user. These robots are based on precise criteria in order to assign a quality rating to each site linked to the query. Here are the basic criteria of these robots to define the ranking of a site on the displayed results.

The popularity rating of the page or website

This is the most important criterion to determine the ranking of the page or website. The crawlers then take into account the number of visitors and incoming links (or backlinks) pointing to the site. The more visitors and backlinks it has, the better the search engines will rank it.

The content of the site and its SEO

For search engines to qualify a site as relevant, its content must be valuable and of high quality. For this, the manager must write content with relevant keywords so that the search engine ranks it among the best. Today, the majority of marketers opt for SEO, or natural search engine optimization, to optimize the content of their site and thus ensure a better place in the results displayed. The crawlers will analyze these keywords according to the requested query and rank the sites with optimized and quality contents.

The organization of the content in the website

This is a criterion that Google, as well as other search engines, take into account in order to identify pages that are likely to satisfy users. Therefore, site managers must organize their content such as titles, images, videos, external links… Search engines evaluate the site’s organization so that the page displayed adapts to all device screens, and the result provides the best ranking of sites with search-related content. This criterion contributes to offering the user results with relevant content and a quality experience.

What are the most used search engines worldwide?

There are different search engines that Internet users use to search the Internet. Here are some examples of the most used search engines, worldwide:

  • Google Search Engine: Google is the giant of search engines that dominate on all devices with access to the internet;
  • Bing: it is the search engine that gets the second place after Google. It is a software set up by Microsoft to challenge the largest of the search engines;
  • Yahoo: is a search engine whose results are influenced by Google and Bing. Yahoo is also the default search engine for Firefox since 2014 ;
  • Qwant: It is a search engine software that guarantees the security of users’ personal data. It proposes a page containing results classified in a vertical menu according to the category of the site: news, images, shopping… ;
  • Yandex: it is a search engine known for operating the largest search engine in Russia and has a market share of about 65% in this country;
  • Ecosia: It is an ecological search engine which aims to reduce the energy consumption of a search. Nevertheless, the results displayed by Ecosia are provided by Bing and Yahoo!
  • Lilo: the software uses the money collected for the cause of the environment as solidarity or social projects.

These programs are all available worldwide, but some are specifically designed for particular browsers such as Microsoft and Bing.

A search engine is activated to offer quality and relevant results to users. Content editors will have to monitor the search engine ranking criteria in order to obtain a better place among the results displayed.

Amandine Carpentier

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