How Do Search Engines Work?

Have you ever thought about how many times a day you open your smartphone in the hope of finding the questions you are interested in on the Internet. The number of Internet users around the world is growing steadily. The total number of Internet users has reached 4.8 billion people, which is about 63% of the total world population.The numbers are huge.

Search engines have become not just a means to find information, they have become an integral part of our daily lives. We use them as a tool for learning, leisure, work, shopping, entertainment and even business.I think the fact that we have come to the point where we depend on search engines for almost everything we do is well known. You may ask me why, the answer is simple – we are used to the fact that any search engine, and Google in particular, can not only find answers to our questions, but also solve our problems in a matter of minutes. However, everything is so simple only from the point of view of an ordinary user.

Each query you enter in the search field is an extremely complex system, a complex algorithm of actions prescribed by the program. So how do search engines work inside, how the system always guesses what exactly you are interested in and what the SEO has to do with it. As I mentioned above – search engines are complex computer programs.

Before they give permission to process your search query and search the Internet directly, they have to do a huge amount of preparatory work, so that when you click the “Search” button, you get a set of exceptionally accurate and high-quality results that qualitatively answer your question or query. What is “preparatory work” and what exactly does it include? It is based on only three key stages. Stage one is information discovery, stage two is information systematization, and stage three is ranking. In the online world this is commonly known as crawling, indexing and ranking.

Stage one : purely scanning

This process involves scanning sites and obtaining information about everything that is contained on them, for example: page title, keywords, type of layout, classification of a particular page, resources to which it refers, etc. This task is the work of special robots – search engines, which are called crawlers. During the search process, they usually start with the most visited servers and the most popular web pages. The very structure of links is extremely important for determining the route these crawlers take.

Their goal is to move from link to link in order to find many interrelated documents. However, very often they just look through all the previous sites to check if new changes have been made. And this process is as cyclical as possible, it lasts minutes, days, years since the very foundation of search engines. Sometimes the “caterpillars” of this huge cyber machine give up. The reason for this is the actual content that can be hidden at a distance of tens or even hundreds of clicks from the main page.


Immediately after all the received data has been assimilated and processed qualitatively, all the selected fragments will be automatically backed up in huge storages. To better understand the process of backing up and storing, I can give a simple example: we have a certain number of books. Going through them all one by one is scanning, and making a list of them together with authors and other related information is indexing. However, this example is only a tiny part of a huge system.

If we extend this “scientific” assumption to the books contained in absolutely all libraries of the world, we will get the result we need – this will be the system of indexing sites.

Ranking and search

Have you ever left a message on your friend’s answering machine? All search engines are also a kind of answering machines. Every time we search for some information on the Internet, search engines automatically look through the available database in order to give you the most relevant result. However, that’s not all. Like a huge assembly line with thousands of hard-working employees, they rank these results with great speed based on the available data about the popularity of websites. That is why such things as relevance and popularity in the SERPs are the most important factors that should always be considered by these search engines in the first place, because they serve to ensure satisfactory performance.

By themselves, ranking algorithms are not unusual, but they are different for different search engines. The system in turn can assign weight to each entry, depending on how it is presented in the title, meta tags or subheadings. The simplest algorithm usually analyzes the frequency of use of the keyword that is being searched for. However, such methods have their disadvantages, as a result they lead to the so-called “keyword stuffing”, when pages are mostly filled with nonsense or information that has no value if they contain a keyword.

When knowledgeable people realized that nothing good would come out of this, they quickly found a way to solve this problem. The concept of links was invented, each of which not only provides the desired information in a matter of seconds, but also does not spam the page with unnecessary information, distinguishing it from others. Now the vast majority of quality search engines are developing and growing daily, filling the Internet pages with only relevant information, and allowing you to access anything from anywhere in the world. It is really interesting to think that the understanding of what we say in a free manner, sooner or later, can make a great revolution in this technology. Using simple, everyday language or slang is the future of search engines. One of the popular sites for natural language queries today is, it prefers simple queries. Perhaps in many years there will be alternative search engines built on levels of query complexity.

So, we figured out how search engines work, what crawlers and your preferences have to do with it.

Now I propose to talk about links. First – links are external and internal. What is their difference?

External links – are links to another domain.

At the bottom of almost every page there is a footer that helps visitors to easily navigate to other pages using both internal and external links in general. Usually, external links are used to point to social media profile pages or article references. A large number of websites use more internal links than external links. Basically, links on a website link to other pages on the same website, as a result creating a huge web of interconnected documents. What is the mission of internal links?

They link all the pages that exist in the same domain and unite them into a coherent system. However, all the activities on the Internet are more related to the functionality of external links. In turn, external links form connections with web pages that exist and function outside of one organization or system. They help to first create and then develop a huge part of the network of billions of pages that exist on the Internet. External links are used for various reasons. For example, you include in your article certain statistics or graphs with precise information that serves as an application or argument and you want to link to an external data source on another website. This not only adds credibility to what you publish, but also contributes to a significant expansion of the Internet.

How search results are displayed

The processes we have already considered earlier, namely scanning and indexing, are automatic and continuous. The index is updated in real time. Data collection and storage also occurs in the background, taking into account all the subtleties of the indexing process.

However, I must say that the results you get after processing the request directly depend on your queries to the search engine.  How does it work visually? For example, you are looking for “the best streaming TV service”, while you type the first word in the search bar – the system is already working at full capacity, namely the search engine matches each word with documents in its index.

But the usual matching of words with indexed pages leads to the issuance of up to billions of documents, which are often inappropriate or irrelevant to your search query. That is why the system itself has to determine how to show you the best matches. And finally we come to the point where things get really complicated – and why SEO is so important. Having already answered a lot of questions, there are still more. How do search engines decide from billions of potential results which ones to show? This is where the ranking algorithm we talked about above comes into play.

Algorithms are a set of rules that all computer programs, without exception, follow to perform a particular process. A ranking algorithm is a huge number of algorithms and processes that work in unison for one purpose.

A ranking algorithm looks for the following factors:

  • Do all words from the search query appear on the page?
  • Do certain combinations of words appear on the page (for example, “best” and “streaming”)?
  • Do the words appear in the page title?
  • Are the words present in the page URL?

These are basic examples, and there are hundreds of other factors that the ranking algorithm takes into account when determining which results to show. These are ranking factors.

Extracting meaning from complexity

Today we have defined many terms and covered some basic SEO issues. Summing up the whole article I would like to note once again that search engines are extremely complex structures that process unimaginable amounts of data every day. They work exclusively with the help of complex algorithms that are designed to understand this data and satisfy user requests.

Thousands of the world’s best software engineers work on detailed refinements and improvements, making companies like Google responsible for advancing some of the most complex technologies on the planet. Modern technologies such as machine learning, artificial intelligence and natural language processing that we discussed above will continue to have a greater impact on search results. You don’t need to understand all the complexity, but by applying a few basic best practices, you can make your website accessible for the words and phrases your customers are searching for.