SEO: Back to the Very Basics

By Gordon Smith on 6-Sep-2017

We're sometimes asked "What is SEO" or "How does SEO work?" It's a big topic but let's start with the very basics. In this article I'll give a high level summary of search engines work, how the position of websites within search engines works is calculated, and touch briefly on how SEO aims to improve position. So if you have no idea of what SEO is, this article is for you!

How do search engines work?

Search engines are indexes of websites. They use special software to automatically visit and store the content of web pages. To get from page to page and site to site, they follow the hyperlinks on those pages. They also calculate and store a huge amount of extra information. This includes:

Which web pages link to which
How long web pages have been online
Where in the world the web pages are hosted
How many times links to those pages have been shared on social media
What the web page contains (text, images and video for example)
What language it is in
To an extent, what the web page is actually about (we'll come to how search engines are getting much better at understanding meaning later)

These are all things the search engines can ascertain from it's own data. But they also measure other important data:

How many people visit each web page
How long they stay on those pages before going away
How many links to each web page there are

Using all this information combined, search engines can form a picture of a web page's popularity and importance.

Your search query

Now the SE has all this information, it can take requests from users to find web pages. A search request is usually called a query. A query is composed of words. Each word is called a keyword and the words combined are called a keyphrase.

When a user issues a query, the search engine matches the query against the content of all the web pages it knows about. Example: "what is the world's tallest mountain".

When faced with a query like this the search engine will consult its index of web sites looking for pages which contain content about tall and tallest mountains. It will tend to find many matches - thousand or millions. Once it has found these matches, it will sort them into what it thinks is the best order.

So how do search engines sort search results?

This is the heart of the matter, and why search engines are so useful. We don't want to spend hours trawling through lists of search results looking for the best one. We want to be presented with the most relevant result first. The search engine uses an algorithm (a bit like a mathematical function) to sort the results. It will typically apply many different criteria. For example, Google uses around 200 different criteria. These criteria are called "signals". The most important signals will be:

Number of links to the web page from other websites
The quality of the websites that link to you
How closely the words on the web page matches the keywords used
Number of shares on social media
Whether the page is brand new or well-established
How long people stay on the page
How fast the page tends to load (especially on mobiles)
When the page was last updated
How often you update your pages

Increasingly search engines take into account personalised factors such as:

What the user has previously searched for and clicked on
If on a mobile, where they use is geographically located
What the search engine has learned about what the user likes and dislikes

There are so many factors that the search engines takes into account that to describe them all would not be "very basic".

How search results are sorted and ranked

Now how do I get my page to the top of the search results?

Finally, we come to the main question! To get your page to the top of the search results, you will need to:

Ensure your content is top quality and really answers users' questions
Ensure you get links from other top quality websites
Keep your website up-to-date and accurate
Doesn't try to use any sneaky tricks to fool search engines (they are professionals and have seen all the tricks!)
Provides a better user experience than other competing pages

It's not easy but with hard work it can be done!