How Do Search Engines Work? (Explained in Detail)

Search engines are our modern-day encyclopedias, our answer machines. They continue to amaze us by evolving and progressing every day. They are our windows to the internet: discovering, ranking, and categorizing billions of webpages according to the search query. Search engines operate advanced algorithms that make decisions on the quality and relevancy of any page. How search engines work, however, is a beautiful but complex process.

As a website owner, you will want to appear on the first page of search results. In order to be visible, your content needs to be visible and easy to identify to search engines. But how are we supposed to know what the search engines look for without knowing how they work? Continue reading our article to learn how search engines work and the factors they are using to filter webpages.

How Search Engines Work: A Brief Explanation

Search engines are several interlinked tools that work together to recognize pieces of web content like images, videos, and website pages based on the search query. They have hundreds of factors to filter out irrelevant content. But before they perform a search, search engines need to understand what kind of information is accessible and what to present to the user.

They perform this excellent task of searching through three primary functions: crawling, indexing, and ranking. 

  • Crawling: It is what search engines do to search the internet for content. Also known as bot or spiders, web crawlers collect the information needed to index a webpage accurately.
  • Indexing: This is when the search engines store and organize the information found. It is the process of reviewing the website data for the positive of negative ranking. 
  • Ranking: Ordering the indexed webpages with search algorithms from most relevant to least relevant on the Search Engine Results Page (SERP). Learn more about SERP.

Decisions are made during this process to determine which website is best to appear on SERP based on the user’s search query. Let us dive into detail on how this process is carried out.

Search Engines Crawling

Search engines base upon crawlers to search for information relevant to the search query. Advanced algorithms automatically decide which website to crawl from between the websites list. The algorithms also decide how many pages spiders will crawl and its frequency.

Crawlers visit each website on the list, in a matter of milliseconds, and create an ever-expanding web of interlinks. Crawlers are the first things you will want on your website to appear on SERP. If crawlers can not identify your page, they will not index it. And an unindexed page will not be on the search results. If you are unsure whether your website is getting crawlers or not, Amazon’s Alexa offers a Site Audit tool that stresses accessibility issues and gives advice on fixing them.

Search Engine Crawling

Search Engines Indexing

Once a spider has crawled a web page, the copy returns to the search engine and is stored in a data center. Data centers are massive, purpose-built groups of servers that act as a container of all the copies of webpages searched by the crawlers. Google owns many data centers spread around the world.

The container of web pages is the Index, and this database provides the search results you see on the search engine. The spiders organize the content into categories such as images, CSS and HTML, text, and keywords. In other words, crawlers need to see what the user sees. This way, bots will understand what is on the webpage and will send it to the database to be indexed.

Search Engine Indexing

Search Engines Ranking

This is the final task of search engines when you type a search query and hit Enter. They sort the indexed webpages by relevancy and return results. The ranking process is carried out by search algorithms that analyze what the user is searching for and which results are the best.

There are various factors algorithms use to sort the information and define the quality of pages in their index. Many of the ranking factors analyze the global popularity of content. Some of those factors are:

  • Quality of the backlinks
  • Mobile-friendliness
  • Frequency of updating
  • Engagement/Interaction
  • The loading speed of the page
  • Internal/outbound links
  • Keywords
  • Quality, unique content

How Do Search Engine Algorithms Work?

As we have stated before, the search engine algorithm is what carries out the whole searching process. If you want to push your website to the top, you will need to learn how the algorithm itself works. Before we dive into the details of the search engine algorithm, here is how Google describes it:

These ranking systems are made up of numerous algorithms that analyze what you are looking for and what information to return to you. And as we have evolved the Search to make it more useful, we have improved our algorithms to evaluate your searches and the results in detail to make our services work better for you.

We will give Google’s algorithm as an example as it is the most popular search engine. The functions of algorithms can be separated into four parts.

  1. It analyzes your words. Thanks to its language models, Google can interpret your intention, and find it in its index. 
  2. It matches your search. Besides understanding what you type, it matches the webpages related to your search query. This is mostly possible by searching for the keywords and their appearance on the webpages.
  3. It ranks pages. As you want to find the best answer to your question on your search, the algorithm brings out the most suitable ones for you.
  4. Search context matters. Not everyone gets the same results when searching for the corresponding keywords. Your search history, settings, and locations will help the algorithm determine what to choose for you.
How Do Search Algorithms Work


Once we have made everything more transparent for you, you must be able to make your website visible to crawlers, and the rest will happen naturally. How search engines work is a miraculous event. Get your website crawlable and indexable with the help of this video that we have found to be helpful.

Frequently Asked Questions About

Backlinks are links on one website that, when clicked, take the user to another site.

Mobile navigation that shows different results than desktop navigation will keep them away for once, which is not optimal.

Yes, the cached version of your page will reflect a snapshot of the last time a spider crawled it.

Müge Özay
Müge Özay

Posts: 31

I graduated from the Department of Management Information Systems at Istanbul Bilgi University. I work with the Dopinger team in the field of digital marketing and SEO. I am sharing the content that I find useful with you.
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