search engines

What are search engines and how do they work?

What is a search engine?

A search engine is an online tool that is designed to search for websites on the internet based on the user’s search query.

Every time a web crawler finds a new webpage through a link, it scans and passes its content for further processing (called indexing) and continues in the discovery of new webpages.

2. Indexing

Once the bots crawl the data, it’s time for indexing – the process of validating and storing the content from the webpages in the search engine’s database called “index”. It is basically a big library of all the websites.

Your website has to be indexed in order to be displayed on the search engine results page. Keep in mind that both crawling and indexing are continuous processes that take place over and over again to keep the database fresh.

Once the webpage is analyzed and saved in the index, it can be used as a search result for a potential search query.

A quick tip: To find all your indexed pages, you can use Google Search Console or you can do a quick check by using the site search operator“”

3. Ranking

The last step includes picking the best results and creating a list of pages that will appear on the result page.

Every search engine uses dozens of ranking signals and most of them are kept as a secret, unavailable to the public.

As Martin Splitt, Webmaster Trends Analyst, said:

“We have over 200 signals to do so. So we look at things like the title, the meta description, the actual content that you’ve got on your page, images, links, all sorts of things.” (Martin Splitt, Webmaster Trends Analyst)

What is a search engine algorithm?

The search engine algorithm is a term used to define a complex system of several algorithms that evaluates all the indexed pages and determines which of them should appear in the search results for a given query.

For example, the Google algorithm uses dozens of factors (many of them are well-known, while some of them are kept a secret) in several areas such as:

  • Meaning of the query (understanding what the user means by using the exact words they used, what is the search intent, etc.)
  • Page relevance (the search engine needs to find out whether the page answers the search query)
  • Content quality (the algorithms determine whether the webpages are an excellent source of information based on internal and external factors; number and quality of backlinks are important factors here)
  • Page usability (considers the quality of webpage from the technical standpoint – responsiveness, page speed, security, etc.)

Search engine optimization

Besides providing useful information for their users, search engines can also help brands to promote their websites.

Optimizing your website for relevant search queries and boosting the search presence of your brand within Google Search is an important part of any online marketing strategy since it can drive more traffic to your web pages.

The sum of all the practices and techniques the website owners do to improve their search rankings is called Search Engine Optimization (SEO).

SEO soup

If we wanted to simplify SEO, we could say it all revolves around the 3 most important factors:

  • Technical optimization
  • Great content
  • Quality backlinks

What are the most popular search engines?

Although there are hundreds of search engines in the world, only a few of them dominate the overall search engine market and remain popular thanks to their quality, usefulness, etc.

search engines market share worldwide

In terms of worldwide popularity, Google has been #1 for years. This is the list of top 5 most popular search engines:

1. Google

Google is the biggest and most popular search engine in the world.

Owned by its parent company Alphabet, Google dominates the search engine market with over 90 percent market share worldwide.

With all its features that include sophisticated algorithms, effective crawling, indexing, and ranking, Google provides excellent search results not only within its own search engine, it powers some other search engines as well (e.g.

2. Microsoft Bing

Bing is the second largest search engine. It was launched in 2009 and it’s owned by Microsoft.

Although it is impossible to compare Bing as a real opponent to Google with only 2 – 3 percent of the overall search engine market share, it is still a great alternative for those who would like to try something different.

Microsoft Bing is in many ways similar to Google, providing search result types like images, videos, places, maps or news.

Although Bing uses the fundamental principles of search engines (crawling, indexing, ranking) it also uses a special algorithm called Space Partition Tree And Graph which is based on the vectors for categorization of information and for answering the search queries.

3. Yahoo!

Yahoo is a popular website, email provider and the third biggest search engine in the world with almost 2% of the overall search engine market share.

Once a very popular and dominant search engine, Yahoo was dropping in value over the years and became somewhat overshadowed by Google.

Nowadays, Yahoo competes with smaller search engines such as Bing or DuckDuckGo.

4. Yandex

Yandex (from the term “Yet Another iNDEXer”) is a search engine that is popular mostly in the eastern countries.

Although it has less than 1 percent of the overall search engine market share, it is one of the most popular search engines in countries like Russia (with over 60 percent of all searches in the country), Turkey, Ukraine or Belarus.

Similar to Google, Yandex provides various types of services including Maps, Translator, Yandex Money or even Yandex Music.

5. Baidu

Baidu is the most dominant search engine in China. Even though its overall worldwide market share is barely 1 percent, it represents over 80 percent of the market share in China with billions of searches every day.

Baidu is similar to Google in many ways. It provides classic blue links with green URLs and shows rich results the same way as Google does.


Let’s answer a couple of frequently asked questions about search engines.

Why is Google the most popular search engine?

Google, as a search engine, has been a leader in its industry for years and is still dominating the search engine market. There are a few reasons why is Google the most widely used search engine.

  • It was one of the first search engines
  • It offers relevant results
  • It is fast
  • It is constantly improved
  • It is connected to several free services

How do search engines make money?

The main source of revenue for search engines like Google comes from various indirect sources. Search engines can monetize their services via:

  • Advertisement – Google uses its own advertisement service called Google Ads thanks to which it can help brands to display their products in the search results and in return takes a small commission every time a user clicks on the ad.
  • Online shopping – search engines can promote various products in their enhanced search results. If a user clicks or buys one of the products, the search engine will in exchange take a small percentage from the purchase.
  • Services – Google incorporates its services (e.g. Play Store, Google Cloud, Google Apps, etc.) with its own search engine and therefore generates revenue via customers who use them.

What was the first search engine?

Archie (from the name “Archives”) was the first search engine created in 1990 by a student Alan Emtage.

Although there were some indexing programs before (like “X.500” or “Whois”), Archie was the first real search engine that was capable of finding specific files on the internet.

Archie worked pretty simply – it looked at the sites available on the internet and indexed them as downloadable files. However, it could not index the content of the sites and therefore the result pages had the form of a simple list.

What is the difference between a browser and a search engine?

Web browser (e.g. Chrome, Firefox, Microsoft Edge, etc.) is a software application that is installed on the computer or a smartphone. The purpose of the browser is to provide a user-friendly interface to display the webpages.

Search engine (e.g. Google, Bing, Yahoo!, etc.) is an online tool available on the website that can be accessed through a web browser. The purpose of a search engine is to provide answers to users’ queries in the form of relevant webpages.