1. What Is A Search Engine?
  2. Types Of Search Engines
  3. How Do Search Engines Work?
  4. Last Words

Are you interested in search engine optimisation but don’t quite know how search engines work? You’re certainly not alone. Search engine optimisation (SEO) is a complex topic, and understanding how search engines operate can be confusing - but it doesn’t have to be! In this comprehensive guide, we’ll explain how search engines work.

What Is A Search Engine?

TechTarget defines a search engine as a “program that searches for and identifies items in a database that matches a specific criteria.”

What a mouth full... 

To put this in plain words, a search engine is like a librarian that helps you find what you need.

For example, if you want information on extreme sports, you can ask the search engine, “What is extreme sports?” Then, the search engine will bring back results related to your query.

Types Of Search Engines

Fun fact: There are three main types of search engines. If you want to know more about how search engines work, it’s important to understand the different kinds.

The three main types are:

  • Web Crawlers
  • Directories
  • Sponsored Links

Now, let’s break down each type in detail so you can get an accurate picture.

Web Crawlers:

Web crawlers are the most commonly used type of search engine. They use a technique called web crawling to find websites on the internet. This process involves sending out automated programs, or “spiders”, which travel through the internet collecting data and information from various sites.

Web crawlers look for particular words, phrases, and other relevant pieces of information that can be used to display the website in a search query. This helps them to index and rank web pages on the internet for users to find more easily.

GoogleBot, for example, is the most popular web crawler. The GoogleBot follows links from one page to another and adds each page it finds to its index.


The second type of search engine is a directory. Instead of crawling the web, as web crawlers do, directories rely on human editors to review websites and decide which ones should be included in the directory.

These human editors look for sites that are relevant to particular topics or keywords so users can find what they are looking for quickly.

The most popular example of a directory was Yahoo! Directory. It featured websites organised into categories by topic.

Sponsored Links:

The third type of search engine is sponsored links. This type of search engine works differently from web crawlers and directories, as it displays results based on advertising budgets.

Sponsored links are paid advertisements that appear alongside organic search results in response to a user’s query. The more advertisers pay for their ads, the higher up they will appear on the page.

An excellent example of a sponsored link search engine is Google Ads, which allows advertisers to bid on keywords and appear in the top search results.

Up until now, in this guide, we’ve discussed what a search engine is and the types of search engines available. Now, let’s have a look at how search engines work to provide relevant results for user queries.

How Do Search Engines Work?

Search engines follow a step-by-step process known as ‘crawling, indexing, ranking, and delivering’. Let’s take a look at each step in more detail:

What Is Crawling?

Crawling is the first step in a search engine’s process. It involves a web crawler (also known as a spider) scanning websites and following links from one page to another. This allows search engines to discover new pages, as well as analyse existing content on the web.

When crawling, the spider will look for certain things, such as titles, headings, images, keywords, and links. This data is then stored in the search engine’s database, ready for indexing.

What Is Indexing?

Indexing is the process of analysing all the data collected during crawling to determine which words are associated with a particular web page or website. The more often a word appears on a page or website, the higher its relevance.

During indexing, the search engine also assigns each page a numerical value according to its content’s relevancy to a query and how often it appears. The higher the score, the more likely that page is to appear in search results.

What Is Ranking?

Once indexing is complete, the search engine will then rank each web page according to its relevance and importance. This is done by using an algorithm that takes into account a variety of factors, such as keywords, the freshness of content, internal and external links, user behaviour on the page (such as time spent on the page), and more.

The pages that have the highest scores are then placed at the top of the search engine results page (SERP). This is where you and everyone around the world want to be.

What Is Delivering?

The final step is delivering, which involves providing users with the most relevant web pages from the database when they enter a query into a search engine. This includes all information related to the search query.

For example, if you searched for extreme sports, the search engine would deliver articles about extreme sports, vendors selling extreme sports equipment, and maybe a video or two about extreme sports.

Search engines have worked hard to perfect their delivery process so that it is as efficient and accurate as possible. As technology continues to evolve, we can expect search engine algorithms to become even better at delivering the most relevant information for each query.

Let’s take a look at Google’s AI-powered Search Generative Experience (coming soon to South Africa). This update to Google’s search engine will use artificial intelligence to present users with information based on the keywords they enter.

If you want to know more about this update, you can read it here on Google’s Blog.

Last Words

If you follow this step-by-step process, you’ll get a better understanding of how search engines work and what they do to deliver the most relevant information to users. 

But it’s important to remember that search engine algorithms are constantly changing, so staying up-to-date with the latest developments is key for success when it comes to SEO.

If you want to learn more about this or get assistance with your website’s SEO, you can reach out to our SEO Pretoria services here at Starbright. We specialise in all things related to on-page SEO, off-page SEO, and technical SEO.