How search engines work – What you need to understand

With search engines like Google, Bing and Yahoo, you can pretty much search everything from ‘marketing agency in London’ to ‘cute dog pics’ – and your search engine will find something relevant to your query. But how? How do search engines find relevant web pages through billions of websites on the internet? Through algorithms and riffling through a lot of data, search engines help us find what we need.

So, how do they work? Well, in this post we’re going to tell you all about how search engines work. For you to better understand SEO and how a search engine compiles data, understanding how they work is key. So, let’s get into how they operate below.

search engines

The two functions of search engines

They serve two purposes:

  1. To compile data and crawl a website, the index it in databases.
  2. To produce results relevant to searchers’ query.

How we use search engines is the second purpose, to type into that little search by and find websites relevant to what we search for. However, the first purpose is how we see those sites, and the order on the search engine results pages is the way they are ranked in relevance to a query.

Collecting the data

In order for search engines to collect data and index it on databases, they use robots, or crawlers, to go across a website and gather relevant data. These crawlers need to use links across a website, in order to get around. Every internal and external link is important, so these crawlers can fully move around a website collecting data. Once the whole site has been crawled, the data is indexed and stored in huge facilities, where it waits until relevant query terms are searched for. Then, the search engine returns the data within a matter of seconds (usually less than 1 second).

Search engines will find the best and most relevant result to your query. Therefore, there must be a way for them to determine website rank and relevance. Before they got smarter with new tech, they simply used to analyse the text on a page – which they still do – but now, they gather so much more. Now, search engines work off popularity. The more a website or page is clicked on, the higher it ranks for the same relevant query. All of this is figured out by an algorithm, which determines the relevance of reach page.

Search engine guidelines

Two of the biggest search engines in the world have guidelines to help websites perform better. Here’s what Google and Bing have to say:


Websites should be made with the user in mind, instead of trying to appease search engines. There’s lots of sneaky things you can do that search engines will pick up on – your site needs to be optimised with the user in mind. Your website needs to have a clear pathway of links around it, with the text being useful, information rich and valuable to the user. You should make sure relevant keywords are included in the copy – without over using them (known as keyword stuffing).


Your URL should have a clear structure in place, with keywords included. Written content needs to be displayed on the site in a way that makes sense, it cannot be hidden in Flash Player or JavaScript etc. Again, you need to include keywords in your content, without keyword stuffing. Your content must be relevant to what users are searching for. Finally, data you want indexed cannot be in images, as it will not be picked up by search engine crawlers.

These are the basics of how a search engine operates, but a lot more goes into SEO work than just this. Understanding the basics of search engines, like Google and Bing, means that you can begin to create a site that will be optimised for search engines. However, this isn’t all there is to do. On-going SEO work is vital for your website, because organically ranking on search engines can be so beneficial for your business.

Around 95% of all click throughs on website are from Google’s first page. If you’re any lower than page 1, you may not be found by potential customers and clients. The first result on search engine results pages usually gets around 32.5% of the clicks, whilst second place has around 17% – the rest of the percentage is divvied up between the other results. So, it’s vital to try and rank as close to the top, for relevant terms, as you can.

Ensuring your website is optimised for search engines, by the set guidelines, means you’ll stand a better chance of ranking. Now you know how a search engine operates, you know what to do. Invest in SEO because it’s vital for online exposure. If your site isn’t appearing on search engines, you run the risk of not being found online.