How do search engines work? Our best guess is that you already know. You punch in the thing you want to know more about, press enter and millions upon millions of result pages appear almost instantly. But do you know how they truly work? The magic behind the curtain? Here’s an in-depth look at how search engines work.
How Do Search Engines Work?
The first thing you need to know on the topic is the fact that, for every search out there, there are three primary stages, as follows. The crawling stage, in which the search engine discovers the content per se. Then there’s the indexing phase, where the engine analyses the content and stores it in larger than life databases.
Finally, there’s the third stage or the retrieval. In this one, the query will retrieve for you only that part of the content which is relevant. The selection happens based on the words you filled in the search box. You then receive said selected content in the shape of web pages that might interest you.
Let’s break down these stages and see what they’re all about.
How Do Search Engines Work – The Crawling
As noted above, crawling is the step that triggers the entire process. It means acquiring data about a particular website. Or a few million, for that matter and to be more exact. However, for the sake of our complete guide on how do search engines work, let’s keep it simple.
The process of crawling virtually scans the website and produces an exhaustive list of everything that is on there. For example, it records the title or name of the page, the links, images, all the keywords it holds, as well as all the other pages to which the main one links. Keep in mind this is a bare minimum of all the information crawling retrieves.
There are also some more modern crawlers which, when activated, proceed to make a cache copy of the page in its entirety.
Still, how does the search engine crawl a website, to be more precise? Well, it has some spiders. No, not the real legged ones, but some automated, crawling bots, which people call ‘spiders.’ Every bot visits and scans every single page extremely fast and it gathers the info on it, as shown above.
Afterward, the little crawler spider makes a list of all the new links it found. It will use them as next places where to crawl. Once it gets there, it scans them all, takes all the links and makes another list of where to go to next. And we’re sure you catch our drift and where we’re going with this.
In fact, it’s a process that may very well never end, as there are countless websites out there.
This is the manner in which crawling works. As a bonus information, you should know that there are some type of sites out there which Google or any other search engine, for that matter, do not index.
The idea translates into the fact that the search engine cannot see them, nor can we. In the past, these websites used to make up what was called the ‘deep web,’ a sketchy part of the online world, partial to wrong doings. That doesn’t happen so much anymore, though, as search engines can see more and more of the online.
How Do Search Engines Work – The Indexing
As we briefly explained in the introduction to this article, indexing is the process through which the search engine takes all that data it collected via crawling and places it into a big database. However, don’t be fooled into thinking that it’s a simple process because you would be terribly wrong.
Let us put indexing into perspective for you. Say you had the manual task of taking every single book you own and writing down on a piece of paper its title, author, and how many pages it has. When you proceed to go through every book for this info, it means that you’re crawling. Moving on to actually writing down the data. That means you are indexing.
Now imagine that you had to do this not only for your personal library but every single library in the world. Impressed? There’s more because doing this is, in fact, the small-scale type of works which Google or any other search engine does.
They keep the data in its entirety in complex and enormous data centers. They house thousands of pentabytes in data and drives.
How Do Search Engines Work – Retrieval and Ranking
We have come to the final step of our guide on how do search engines work. The last chapter is what you actually get to see after you have pressed enter on your search. If you thought the other two steps were intricate, wait until you read about this one.
Tip – if you are interested in the topic how do search engines work, this final step is the most important one because it matters most to users like you and me. Apart from that, it is also the level at which most search engines differ from one another. For example, some of them work by using keywords. Others let you ask questions, while some more types have advanced features. The latter can mean anything from using a filter such as how old the content is to keyword proximity.
Even so, there were some talks a few years ago that Bing had copied a few results from Google, but there is no way of telling that for sure.
There’s also the ranking algorithm. This process fundamentally checks the thing that you searched. Then it compares it to billions of websites and pages. It wants to see just how relevant it is. Just to give you an idea of how complex and complicated this procedure is, in fact, here’s a little nugget of information. Companies all over the world go to great lengths to make sure that no one will ever find out their private ranking algorithm.
The first reason for which they do this is the competitive advantage. Evidently, if, quality-wise, they are the ones who give you the best results every single time you perform a search, you will come back to them. You will be a faithful user. You will be a faithful user.
Second of all, everyone wants to prevent so-called ‘gaming’ of the system itself. In other words, no search engine should receive unfair advantages over another one. They should not get prejudicial optimization either so that they cannot use it for marketing purposes.
If people manage to find out how the system works from the inside, then they will try to hack it and make money off of it in a dishonest way.
Why is ranking first on a page so important? That’s because everyone clicks on the first result that they see on the results page. Here’s an age-old joke for you which is still relevant today and for our current predicament. If you want to hide something in a place where no one will ever find it, where do you hide it? On the second page of Google, of course.
Here is our complete guide on the topic how do search engines work. People tend to take a search engine for granted but, as you can well see, it has more layers and levels than one could possibly imagine.