Lifestyle

How a search engine works

David Nthua 11th May, 2026 03:47 PM

The internet feels endless until a search bar appears. A blank white space. A blinking cursor. A few typed words.

Then suddenly, in less than a second, millions of webpages are reduced into a carefully arranged list of answers, videos, images, maps, news stories, shopping suggestions, and recommendations that somehow feel strangely familiar to the person searching.

For many people, this feels almost magical.

But behind every Google search lives one of the most sophisticated systems humans have ever built.

That is why two people searching the same thing may never see exactly the same results.

A person sitting quietly while texting a message on their phone.PHOTO/Grok

Search engines first crawl the internet like digital explorers

Before Google or other search engines can show results, they must first discover webpages.

They do this using automated programs called crawlers or spiders.

These bots move across the internet by following links from one webpage to another, scanning text, images, videos, titles, keywords, and page structures. The collected information is then stored inside massive databases called indexes.

Think of the index as a giant digital library catalogue containing billions of webpages sorted into categories.

According to Ahrefs search engine guide, search engines mainly work through three stages: crawling, indexing, and ranking.

Crawlers discover content, indexes store it, and ranking systems decide what appears first after a search.

Without crawling, the internet would become invisible to search engines.

The bots are constantly walking through the web like librarians trying to catalogue an ever expanding universe.

SEO concept illustration showing the acronym “SEO” split into three blocks, with the words “Search”, “Engine”, and “Optimize” around it, plus icons of a magnifying glass, gears, and a rising analytics chart in the background. PHOTO/Pexels

Ranking systems decide what appears first

When someone types “best media houses in Kenya,” Google does not search the internet live from scratch.

Instead, it quickly scans its already built index and ranks pages using algorithms.

These algorithms examine hundreds of signals, including:

Relevance of keywords
Quality of content
Website authority
Freshness of information
User engagement
Location
Device type
Search history
Language preferences

The goal is simple.

Predict what the user most likely wants.

That prediction system is why search results feel personal instead of random.

Why Google may show K24TV first to one person and not another

Imagine two people searching “best media houses in Kenya.”

One person lives near Nairobi and regularly watches videos from K24 TV on YouTube, follows the station on Facebook, and frequently searches entertainment news.

Another person spends more time reading business newspapers and searching political commentary.

Even if both type the same words, their search results may differ.

Google explains in its official help documentation that search results can be influenced by past searches, clicked results, location, and activities connected to a Google account.

A professional sits at a desk managing their online presence through a professional networking profile visible on a laptop screen. PHOTO/Gemini

According to Google’s support page, users may also receive personalized recommendations for stories, webpages, movies, and Discover feed content based on previous interactions and saved activity.

So if someone repeatedly interacts with media content linked to K24 TV, the algorithm may begin interpreting that behaviour as interest.

Your location strongly affects search results

Search engines pay enormous attention to geography.

According to Google’s legal support documentation, location helps Google deliver more useful nearby results, even when users do not type a location directly into the search.

If someone in Nairobi searches “best media houses,” Google may prioritise Kenyan companies or businesses physically closer to that region.

The system estimates location using several signals including:

IP address
GPS data
Device settings
Previous search locations
Google account activity

This is why a person in Nairobi searching “restaurant” sees Nairobi restaurants while someone in London sees London options instead.

According to the Central European University guide on personalized Google results, Google has used location history and browser cookies for personalization since expanding the system widely in 2009.

Location quietly shapes the internet around the user like invisible gravity.

Your browsing history trains the algorithm

Search engines remember behaviour.

If someone frequently watches media interviews on YouTube, clicks news articles from certain publishers, follows entertainment pages on Facebook, or repeatedly visits similar websites, the algorithm collects signals from those patterns.

According to Practical Ecommerce’s analysis of Google personalization, search history and previous interactions help Google interpret user intent and influence future rankings and recommendations.

For example, someone who constantly searches technology news may begin seeing more tech related suggestions inside Google Discover or autocomplete predictions.

A football fan may see sports headlines more often.

A person researching universities may suddenly notice education advertisements everywhere.

The internet slowly reshapes itself around repeated behaviour.

Not because the machine understands people emotionally, but because it calculates probability.

Cookies quietly help websites remember users

One of the major tools behind personalization is cookies.

Cookies are small files stored inside browsers that help websites remember user activity, login sessions, preferences, and interactions.

They are partly why someone who searches for shoes may later see shoe advertisements across unrelated websites.

According to the CEU guide on Google personalization, cookies help Google personalize results even for users who are not logged into Google accounts. (ceu.libguides.com)

Cookies help search engines connect behavioural dots over time.

The more signals collected, the more tailored the experience becomes.