If you’re a developer, designer, small business owner, marketing professional, website owner or thinking of making a private blog or website for your business, then it’s extremely important for you to learn how search engines work.

Having a transparent understanding of how search engines work, can assist you in creating an internet site that search engines can understand. 

It’s the primary step you would need to take before you even start handling program Optimization (SEO) or the other SEM (Search Engine Marketing) tasks.

How do search engines work?

What does a Search Engine Do?

Have you ever wondered how many times in a day do you employ Google or other search engines to comb through the web?

Is it 5 times, 10 times, too many times to keep count? Did you know that Google alone handles almost 2 trillion search queries per year?

The numbers are huge. Search engines have become an integral part of the 21st century lifestyle. Search engines today are used for learning, shopping and all kinds of fun activities. Aside from that, they have also become a very important tool for businesses.  

It’s not an exaggeration to mention that we reached have reached a point of time where we rely on search engines for nearly anything we do.

And the reason this is happening is very simple. We know that search engines have answers to all of our questions and queries, no matter how obscure, esoteric or eccentric they are.

What happens  once you enter a query in the search box and click on search? How do search engines work internally and how do they decide what to point out within the search results and in what order?

Here’s how it goes:

Step 1: Crawling

Search engines are loaded with a large number of computer programs known as web crawlers. As you would imagine, that’s how crawling gets its name. The purpose of web crawlers is to find information that is available for public consumption on the world wide web.

To simplify a complicated process, it’s enough for you to know that the job of these web crawlers (also known as search engine spiders), is to scan the Internet and locate the servers that host the websites.

They create an inventory of all the web servers to crawl, the amount of internet sites hosted by each server, and then start work.

They visit each website and by using different techniques, they  seek out what percentage of the pages they need, whether it’s text based content, images, videos or the other format (CSS, HTML, javascript, etc).

When visiting a website, besides taking note of the number of pages, the web crawlers also follow any links (either pointing to pages within the site or to external websites), and thus they discover more and more pages.

They do this continuously and they also keep track of changes made to a website so that they know when new pages are added or deleted, when links are updated, etc.

If you’re taking under consideration that there are about 130 trillion individual pages on the web today and on an average, hundreds of thousands of new pages are published on a daily basis, you can clearly figure out how mammoth of a task it is.

Why care about the crawling process?

While optimizing your website for search engines, you must ensure that the search engines are able to access it correctly. If the search engines are unable to ‘read’ your website, they won’t be able to list it in their rankings. This will result in poor traffic for your website.

There are a variety of things to do to ensure that crawlers can discover and access your website in the fastest possible way.

If there are some pages on your website that you don’t want web crawlers to access, specify them in the Robots.txt file. For example, pages like your admin or backend pages and other pages you don’t want to be publicly available on the web .

Big search engines like Google and Bing have tools (Webmaster tools) which you can use to give them more information about your website (number of pages, structure, etc) so that they don’t have to find it themselves.

Use an XML sitemap to list all important pages of your website in an order that you want. This will help the crawlers know which pages to watch for changes and which to ignore.

Step 2: Indexing

Crawling alone isn’t enough to make a search engine work.

Information identified by the crawlers must be organized, sorted and stored in order that it can be  processed by the program algorithms before it’s made available to the end-user.

This process is called Indexing.

Search engines don’t store all the knowledge found on a page in their index but they keep things like: when it had been created/updated, title and outline of the page, type of content, associated keywords, incoming and outgoing links and tons of other parameters that are needed by their algorithms.

Google likens its index to the index present at the end of a book. 

Why care about the indexing process?

It’s very simple, if your website isn’t in a search engine’s index, it’ll not appear as a result for any searches.

This also implies that the more pages you’ve got within the program indicess, the more are your chances of appearing within the search results when someone types a question .

In order to rank within the first 5 positions of the SERPs (search engine results pages), you’ve got to optimize your website for the search engines through a process called Search Engine Optimization or SEO.

How to find what percentage pages of your website are included within the Google index?

There are two ways to do that.

Open Google and use the location operator followed by your website’s name. You will determine what percentage of the pages associated with the actual domain are included within the Google Index.

Step 3: Ranking

Search Engine Ranking Algorithms

The third and final step within the process is for search engines to make a decision about which pages to point out within the SERPS and in what order when someone types a question in the search bar.

This is achieved through the utilization of program ranking algorithms.

In simple terms, these are pieces of software that have a variety of rules that analyze what the user is trying to find and what information to return.

These rules and decisions are dependent on what information is out there in their index.

How do search engine algorithms work?

Over the years program ranking algorithms have evolved and have become really complex.

At the start, it had been as simple as matching the user’s query with the title of the page but this is often not the case.

Google’s ranking algorithm takes into account more than 255 rules before making a decision and nobody knows for sure what these rules are.

And this includes Larry Page and Sergey Brin (Google’s founders), who created the original algorithm.

Things have changed a lot and now machine learning and computer programs are responsible for making decisions based on a number of parameters that are outside the boundaries of the content found on a web page.

To make it easier to know, here is a simplified process of how search engines ranking factors work:

1: Analyze User Query

The first step is for search engines to know what information the user is trying to find.

To do that, they analyze the user’s query (search terms) by breaking it down into a wide variety of meaningful keywords.

A keyword may be a word that features a specific meaning and purpose.

For example, once you type “How to bake a chocolate cake”, search engines can deduce from the combination of words “how-to” that you are trying to find instructions regarding baking a chocolate cake. The search engines will then display the results featuring cooking websites with instructions and recipes.  

If you look for “Buy refurbished ….”, search engines know from the words buy and refurbished that you are looking to shop for something refurbished and therefore the returned results will include eCommerce websites and online shops that deal with refurbished items.

With the power of machine learning, search engines have developed the ability to associate keywords together. For example, they know that the meaning of this query “how to change a light bulb” is the same as this “how to replace a light bulb”.

They are also clever enough to interpret spelling mistakes, understand plurals and in general, extract the meaning of a query from natural language (either written or verbal in case of Voice search).

2: Finding matching pages

The second step is to look into a search engine’s index and decide which pages can provide the best answer for a given query.

This is a really important stage within the whole process for both search engines and web owners.

Search engines need to return the best possible results in the fastest possible way so that they keep their users happy and web owners want their websites to be picked up so that they get traffic and visits.

This is also the stage where good SEO techniques can influence the choice made by the algorithms.

To give you a thought of how matching works, here are some of the key factors:

Title and content relevance – How relevant is the title and content of the page with the user query.

Type of content – If the user is searching for images, the returned results will contain images and not text.

Quality of the content – Content needs to be thorough, useful, informative, unbiased and cover both sites of a story.

Quality of the web site – The general quality of an internet site matters. Google will not show pages from websites that don’t meet their quality standards.

Date of publication – For news-related queries, Google wants to show the latest results so the date of publication is also taken into account.

The popularity of a page – This doesn’t have anything to do with what ratio of traffic a website has but how other websites perceive the actual page. A page that features a lot of references (backlinks) from other websites is taken into account to be more popular than other pages with no links and thus has more chances in getting picked up by the algorithms. This process is also known as Off-Page SEO.

Language of the page – Users will be able to access pages in their language of choice. That language of choice doesn’t have to always be English. 

Webpage Speed – Websites that load fast (think 2-3 seconds) have a little advantage compared to websites that are slow to load.

Device Type – A desktop specific site is going to be extremely ungainly and cumbersome to view and access on a mobile device. Hence, a search engine will show results featuring mobile friendly sites when the search query is made via a mobile device.

Location – Users checking out leads to their area, such as “microbreweries in downtown Boston” are going to be shown the results that are specific to their location.

That’s just the tip of the iceberg. As mentioned before, Google uses a total of 255 factors in its algorithms to make sure that its users are happy with the results they get.

Importance of knowing how search engine algorithms work

In order to direct traffic from search engines, your website must appear within the top positions on the primary page of the results.

It is statistically proven that the majority of users click one of the top 5 results (both desktop and mobile).

Appearing within the second or third page of the results won’t get you any traffic in the least .

Increased website traffic is simply one of the numerous advantages of SEO, once you get to the highest positions for keywords that add up for your business, the added benefits are far more.

Knowing how search engines work can assist you with adjusting your website and increasing your rankings and traffic.

Search engines have become very complex computer programs. Their interface could also be simple but the way they work and make decisions couldn’t be further from it..

The process starts with crawling and indexing. During this phase, the program crawlers gather the maximum amount of information that is possible from all the websites that are publicly available on the web.

They discover, process, sort and store this information utilizing a format which is then employed by program algorithms to form a choice and return the simplest possible results back to the user.

The amount of knowledge they need to digest is immense and therefore the process is totally automated. Human intervention generally ends at the method of designing the principles to be employed by the varied algorithms but even this step is gradually being replaced by computers through the help of artificial intelligence.

As a webmaster, your job is to ensure that the crawling and indexing job of search engines ins made easier by creating websites that have an easy and clear structure.

Once search engines can “read” your website without issues, you need to ensure that you give them the right signals to help their search ranking algorithms pick your website when a user types a relevant query.