What is a search engine

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A search engine is a vital tool provided by the internet. It compiles information in its database, which is activated when users conduct searches using keywords or phrases. This process generates results that meet the user’s needs.

Definition of a Search Engine

Also known as a searcher, a search engine is a computer system designed to search for files stored in a database using spiders or bots. When a search engine receives a query, it searches its database and displays the results on a search engine results page (SERP). If there are multiple results, they are ranked according to their relevance.

The Purpose of a Search Engine

Search engines allow users to find content on the internet using keywords. Although the market is dominated by a few major players, there are numerous search engines available. When a user enters a query, the search engine returns a SERP, ranking found pages in order of relevance. The way this ranking is determined varies among search engines.

Search engines frequently update their algorithms (the programs that rank results) to enhance user experience. They aim to understand how users search and provide the best possible answers to their queries. This involves prioritizing pages of higher quality and relevance.

Given the vast amount of information available on the internet, search engines are an essential technology for today’s network functioning.

Types of Search Engines

Search engines can be categorized based on the type of information they gather:

  • Web Page Search Engine: It returns the most relevant web page in response to a search.
  • Image Search Engine: This engine tracks images and displays a mosaic of relevant results.
  • Video Search Engine: It analyzes videos and shows those deemed relevant to the search.
  • File Search Engine: This engine returns results based on the name or type of file.

By understanding these different types of search engines, users can more effectively navigate the vast digital landscape of the internet.

How Search Engines Work

Understanding the functionality of search engines involves three key steps:

1. Crawling

Search engines use software pieces known as web crawlers to locate publicly available information on the internet; hence the name of the process. These web crawlers are sometimes also referred to as search engine spiders. The process is intricate, but essentially, these crawlers/spiders find web servers (also known as servers) hosting websites and proceed to investigate them.

A list of all servers is created, determining how many websites each server hosts. The number of pages on each website and the nature of their content, such as text, images, audio, video, are also identified. Crawlers also follow any links the website has, whether internal links pointing to pages within the site or external links to other websites, using them to discover more pages.

2. Indexing

The information found by crawlers is organized, sorted, and stored to be later processed by algorithms and presented to the search engine user. This is known as indexing. Not all information on a page is stored by the search engine, but only essential information necessary for algorithms to evaluate the page’s relevance for ranking purposes.

3. Ranking

When a query is entered into a search engine, the index is scrutinized for relevant information, which is then hierarchically ordered by an algorithm. This ordering of the search engine results pages (SERP) is known as ranking.

Although most search engines provide tips on how to improve your page’s ranking, the exact algorithms they use are well-guarded and change frequently to prevent misuse. However, by following the best practices of search engine optimization (SEO), you can ensure that:

  • Search engines can easily crawl your website. You can also request them to crawl new content.
  • Your content is indexed for the correct keywords so it can appear in relevant searches.
  • Your content can rank higher in the search engine results pages (SERP).

By understanding and applying these principles, you can effectively enhance your website’s visibility and accessibility in search engines.

Search Engine Directories

Some niche search engines function as directories for specific types of content. This means they only display results for content that is manually added. They don’t crawl the web. SEO tactics can still be used to rank high in relevant queries within these search engine directories. See the types of search engines.

Rich Media Search Results

Universal or “blended” search is how search engines present different types of content in search results to users. In addition to traditional text page results, the SERP will also display rich media content such as images, videos, maps, articles, and shopping pages.

Having various types of content on your website, such as an instructional video on how to use your product or a blog, could affect your chances of appearing on the results pages and how high you rank.

You can use “structured data” on your website to help search engines understand and display specific types of content. This is code added to the HTML markup. Using structured data means information like review ratings, images, addresses, and phone numbers can appear on the search engine results page.

10 Examples of Search Engines

1. Google

Google is by far the world’s largest search engine. It handles over 5 billion searches each day and held more than a 90% market share as of August 2019. Originally developed by Larry Page and Sergey Brin in 1997, Google has been so successful that it has become synonymous with online search services, even entering the dictionary as a verb, with people using expressions like “I googled it” when searching for something online.

2. Bing

The origins of Microsoft’s search engine, Bing, can be traced back to the company’s earlier search engines, MSN Search, Windows Live Search, and Live Search. Bing was launched in 2009 with high hopes of surpassing its rival Google, but despite attracting many fans, things haven’t exactly panned out that way. Nonetheless, Bing is the third-largest search engine in the world after Google and Baidu. It is available in 40 different languages.

3. Yahoo!

Yahoo! Search is another major player in the world of search engines. However, for much of its history, it provided the user interface but relied on others for powering the index and web search. From 2001 to 2004, it was powered by Inktomi and then by Google. Since 2004, Yahoo! Search was independent until a deal was reached with Microsoft in 2009 whereby Bing would power the index and search.


Originally known as Ask Jeeves, is a bit different from Google and Bing as it uses a question-and-answer format. For several years, focused on becoming a direct rival to the major search engines, but today, answers are obtained from its vast archive and user contributions, along with the help of an unidentified external search provider.

5. Baidu

Founded in 2000 by Robin Li and Eric Xu, Baidu is the most popular search engine in China and the fourth most visited website globally, as per Alexa rankings. Baidu’s roots are in RankDex, a search engine previously developed by Robin Li in 1996. Besides its Chinese search engine, Baidu also offers a map service called Baidu Maps and more than 55 internet-related services.


AOL, now known as Aol. and originally as America Online, was a significant player in the early days of the internet revolution, providing dial-up service to millions of Americans in the late 1990s. Despite AOL’s decline as broadband gradually replaced dial-up, AOL’s search engine is still used by a significant minority of searchers. On June 23, 2015, AOL was acquired by Verizon Communications.

7. DuckDuckGo

DuckDuckGo (DDG) has some features that set it apart from its major competitors. It has a strong focus on protecting the privacy of searchers, so instead of profiling users and presenting them personalized results, it provides the same search results for any given search term. There’s also an emphasis on providing quality over quantity regarding search results. DDG’s interface is very clean and not overloaded with ads.

8. WolframAlpha

WolframAlpha markets itself as a computational knowledge engine. Instead of responding to searchers’ queries with a list of links, it provides mathematical and scientific answers to their questions, using “curated data” obtained externally. Launched in 2009, WolframAlpha has become a valuable tool for academics and researchers.

9. Yandex

Launched in 1997, Yandex is the largest search engine in Russia and the fourth most popular website in the country. Beyond Russia, the search engine also has a significant presence in Ukraine, Belarus, Kazakhstan, and other Commonwealth of Independent States countries. In addition to search, Yandex offers many other internet-related products and services, including maps and navigation, music, e-commerce, mobile applications, and online advertising.

10. Internet Archive

The Internet Archive offers free public access to a wide range of digital materials. It’s a nonprofit digital library based in San Francisco and is a great tool for tracing the history of domains and seeing how they have evolved over the years. In addition to websites, one can also find software applications and games, movies/videos, music, moving images, and a vast collection of public domain books. The Internet Archive also campaigns for a free and open internet.

Juan Esteban Yepes

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