Search engines work by simply crawling billions of pages using the web crawlers they have developed. These are commonly referred to as search engine spiders or bots. A search engines spider then navigates the web by following links on a new web page it discovers to find new pages and so forth.
This is an important piece of knowledge that many new SEOs miss out on:
But understanding how search engines work is paramount!
Because you need to know how the system works in order to try and leverage it!
You can’t fix a car’s engine problem without knowing what’s going on under the hood…
… and the same rules apply for all search engines.
But, you don’t need to know everything about search engine algorithms either.
I’m going to take you through how search engines work step by step. Let’s start with the search engine essentials to lay the foundation for a successful SEO career.
What Will I Learn?
How Google Works & How They Rank Your Page
Google’s search engine works around these two main functions:
Crawling and Indexing
We will be looking at these in more detail in a moment.
Search engines use their own search algorithms, so if you appear in the top positions in the search engine results page for one search engine this doesn’t necessarily mean you will for all search engines.
Some place a heavy focus on content quality, others user experience and others link building. Understanding what the search engine wants is critical to your success in the SERPs. We’ll look closer at this shortly. But for now, understand that:
Google is the pioneer of many techniques you will see in this guide.
- They have 72.86% of the global search engine market.
- And “to Google” is an official verb in the English dictionary.
As you can see Google dominates the search engine world. But how does the search engine we all know and love function?
It’s actually pretty simple and happens in a 2 stage process-
- Crawling: First Google “crawls the web” finding pages to add to their database
- Indexing: Then results are organised or “indexed” and added to their database
On a basic level, think of it like someone creating a huge library of books.
- Crawling is finding new books to add to that library.
- Indexing is putting the books you do have in a specific order (like genre or author).
The only difference between a library and Google – is that Google has billions of books.
What Is Crawling?
When you enter a search query in the search engine, you might assume that Google hunts through the entire world wide web in that moment.
What’s really happening is that the search engine web crawler has compiled a huge database of pages and you are searching that database, NOT the entire world wide web.
The database is made up of pre-approved websites that Google has checked over and deemed safe for its users. So you won’t find anything dodgy from the ‘dark web’ for your search query when using Google.
Why does Google do this?
- It can access this database reliably
- It provides a quicker and more user-friendly experience
- It allows Google to add its own “tags” to these pages and provide relevant results
These web crawlers have 2x jobs-
- Find new web pages to index
- Scrape information about each web page
But how do they find websites, get access and recover that information? Well, it’s not actually as complex as you might think…
How Does A Crawler Work?
All websites are part of a network called the World Wide Web which is basically like a huge spider web spread all over the world.
The only difference is the world wide web is held together by links (also known as hyperlinks or backlinks).
And search engine crawlers (or spiders) use these links to travel around the web and discover new content!
Once web crawlers find a new page, they start reading all of the content and code of the page.
In the ideal world, we want the code to be as easy as possible for Google to interpret and understand. Which is where a website owner will perform SEO (search engine optimization).
The crawling process isn’t human-manned and each web crawler works autonomously (using machine learning from the search engine algorithm) to decide whether pages they find should be added to the Google index or not.
Crawlers know that sites where you can buy guns and drugs shouldn’t be added to their database.
But once a web crawler has decided that a page should be added to the database, it’s time for a site to enter the second stage of the process – indexing.
What Is Indexing?
Once a website has been crawled, it’s time to for it to be added to the database.
Indexing is where a search engine files away what’s been found and “tags” it.
(It’s a little more complex than that, but tagging works for now).
Think of it in terms of the library example I gave earlier:
If a box of assorted books is dropped off at a library, they will be organised, tagged and placed into their relevant sections-
Let’s say you’re interested in learning French verbs.
You might go along to Google and enter the search query “French verb list”.
The search engine will search its database for the pages that match that search term:
(in a matter of seconds)
(Note: To complete more specific research, you can also exclude words from Google search to find exactly what you want quickly).
There is a range of factors that determine why those pages show up in that order.
These factors vary depending on the search engine you’re using for example Amazon’s ranking factors are very different to Google’s (more on that later).
First, just understand that the “indexing” process is fluid and as websites grow/add new content/delete new content – it will be re-crawled and re-indexed to provide relevant results for the search queries.
You can get your web page indexed quicker by submitting your XML sitemap to Google Search Console.
Why Do Some Pages Show Up Higher Than Others?
As I briefly mentioned earlier, search engines work on an algorithm that determines the order the pages appear.
That’s a series of equations that are based on different factors that help the computer decide where each piece of content should rank.
With Google, the simplest way I can explain it is through the concept of voting. In its very basic essence, the more “votes” a website has – the higher it ranks.
Let me explain it in more detail with a live example. If you wanted to learn how to make money through Fiverr, it’s likely you would enter a search query like this in Google-
And you’ll find is that lots of web pages show up. But there is one at the top.
That’s my how to make money on Fiverr tutorial:
That means of all the pages that relate to that topic, my site has the “most votes”
But how do websites get these “votes”?
Well… “Votes” are otherwise known as backlinks meaning that when one website links to another website, they are essentially “voting” for it.
For example Niche Pursuits voted for my article when they linked to it-
But that’s not the only vote/backlink that page has.
It also has votes/backlinks from 83 other websites-
And for the most part it’s these votes/backlinks that are driving the number #1 position in the search engine rankings.
It’s not quite as simple as that because not all “votes/backlinks” are created equal. The bigger the site and the more well known it is, the more weight their “vote” carries.
If you were to get a link from a big media outlet like The New York Times or The Guardian, it would carry significantly more weight than a link for a brand new unestablished blog.
I’ll show you how all of this pieces together later. But for now:
Remember that in general the more “votes” a page has, the better and that not all “votes” are created equal.
How Other Search Engines Work And How They Differ
How do other search engines work in comparison to Google?
Many “web” search engines use (like Bing) similar search engine algorithms.
They will crawl and index web pages to use in their search results.
BUT they each have different ranking factors to consider which I will talk about in a minute.
Because there are also other types of search engines you should be aware of like-
Which is another reason SEO isn’t dead !
And as long as search engines exist, we will be able to optimise for them.
How Amazon Works
Amazon is one of the world’s leading product search engines!
They offered hundereds of millions of products on their site and it’s internal search engine algorithm A9, has one main mission:
Showing the right products to the right customers.
Whilst this may sound like Google’s philosophy:
Startupbros point out in their guide to ranking on Amazon, they’re slightly different.
- Google says, “What results most accurately answer the user query?”
- Amazon says, “What products is the searcher most likely to buy?””
This is a huge difference because Google’s search engine relies on spiders to collect and organise external data.
Whereas Amazon’s search engines rely on internal data that is fully focused on serving their own self-interest.
(Meaning: They want to sell the most products per person)
And Amazon does that by making sure the products you are most likely to buy, show up at the top of its search results.
They use many different factors to figure that out such as-
- How many people have previously bought a product (the conversion rate)
- How well it fits the needs of the buyer (the relevancy)
- The previous actions of the buyer (what they are likely to want to buy this time)
- The overall rating and satisfaction the product provides (how other buyers felt)
This information enables them to show the most buyable product at the top of the page.
To give you an example:
If I was to search French learning books:
That would give me this set of results.
Can you work out why?
Trying to figure out why is why search engine optimisation exists, because search engines aren’t big on sharing their ranking secrets.
But by observing results and applying a bit of intelligent thought, we can figure out what is happening-
- The books closely match the keywords I used
- These books are targeted at older learners (I’m logged into my account as an adult)
- They have lots of high ratings (35 to 84 ratings each which is social proof)
- There are tons of positive reviews
- They are affordable (it’s not a product where I’d want to pay $300+)
- They come from a reputable source I’m likely to trust (Collins is a huge UK brand)
And Amazon knows that! Their algorithm automatically optimise results to make sure the perfect product is in front of me when it needs to be.
You can figure out how other search engines work as well just by observing results and applying intelligent thought.
What Do Search Engines Want?
All search engines have a target goal with the information they provide. They all want to meet the needs of their audience.
But these needs vary for each search engine…
Is to provide you the most accurate answer/solution to your problem.
Whether that’s finding the local news, finding out which nickname Kanye West is now using or planning your wedding.
Is to show you the right product for you to buy.
It finds quality products that meet your needs, backed by a history of buyer signals and ratings (with fast delivery).
Is to show you the most relevant video.
Whether that’s a tutorial on brewing coffee or watching gamers play. This keeps user engagement in action and watching ads!
Is to pair you with the right answer to your search terms.
Whether that’s a question that already exists or a question you are asking for the first time.
Trust me when I tell you this:
Taking time to observe and understand what a search engine wants for their users will make your life much easier as an SEO.
Because once you know that, all you have to do is optimise for that!
(If you want to dive deeper into SEO, I recommend you check out my list of SEO books).
Wrapping It Up
If you want to become a successful SEO…
Knowing how a search engine works is one of the most important steps. I am going to cover more technical aspects with you soon.
For now let’s quickly recap what you’ve learned:
- Google’s database is created by crawling and indexing websites
- Crawling is when spiders follow links to discover new webpages
- Indexing is when Google adds new website content to it’s database and adds topic tags
- Many factors influence how sites appear in Google for search terms, the main one is links
- Each backlink to a page counts as one “vote” for that page, the more votes the better
- Not all backlinks (votes) are created equal, links from high authority pages count for more
- Understanding a search engines goal helps you understand how they work and how to optimize your site
…let’s get our hands dirty by taking a deep dive into Google ranking factors.
Please feel free to ask any questions you have in the comments below…