How Do Search Engines Actually Work? (Updated 2021)

How Do Search Engines Work?

The internet is a huge place, filled with different web addresses, or better known as an URL. It looks simple to an unsuspecting user most of the time. You type in something to a search bar, you wait for a few seconds, and you get a list of results of relevant pages. This deceptively short and rapid search process is the resulting effort of the heavy lifting on the backend of the search algorithm.

A search engine has to record, categorise and sort through all of the available URL on the net. So how does it do that and live up to its name as a Search Engine?

The short answer is keywords.

But before all that, we can start by understanding the primary functions of search engines.

Almost all search engines can be understood by their three primary functions:

  1. Crawling
  2. Indexing
  3. Ranking

Search Engine Crawling

Crawling is the discovery process in which search engines send out web crawlers to find new and updated content, crawling billions of pages. These web crawlers are more popularly known as “bots” or “spiders”.

Any type of content can be crawled in one way or another. Webpages, images, videos, PDF files; regardless of the content, as long as there is a link for it, it can be crawled.

The bots usually start off by pulling out a few web pages, and then enter the links on those pages, transporting them to other websites. The process is then repeated, crafting a network and database of URLs, mapped to each other. These contents are tagged as related content, and further ranked on the level of relevance with other metrics, such as site traffic, user retention rate, click-through rate, and other SEO signals.

Sometimes, especially for newer pages, the bots might only pick up a portion of your existing website. It could be a landing page, or a ‘Contact Us’ page or a blog article.

Some web pages may form a better impression to the bot algorithm due to the number of inbound links it has directed to it. On the other hand, other web pages may be obstructed or unoptimized, leaving it to be neglected by the digital world.

Nevertheless, it is important to allow search engines to discover and crawl for most of your web pages. All important parts of your website should appear healthily on Google. Having just your home page appear and indexed by Google is a cause for worry.

A search engine can sometimes only end up with finding parts of your site by crawling, but other pages or sections might be obscured for one reason or another. It is important to make sure that search engines are able to discover all the content you want indexed, and not just your homepage.

When crawling the URLs, a crawler may encounter errors. Google Search Console has a “Crawl Errors” report to show you any form of crawl errors. This could come in the form of crawl errors or not found errors. One of the most common crawl errors many may encounter is the infamous Error 404. Server error codes can also be fairly common. You could also access other metrics and server log files, which can be essential in understanding your website better and formulating your SEO strategy.


What is a Robot.txt file, you may ask.

Robots.txt files are a part of the root directory of websites and is the technical element responsible for suggesting to the algorithm on which aspects of your site should and should not be crawled.

If a robots.txt file is missing or not found, bots will usually proceed to crawl the entire site. Finding a robots.txt will trigger the algorithm to follow suit with the instructions on the .txt file. However, not all web spiders are law-abiding, robot.txt-following web citizens. Malicious bots such as scrappers follow the same approach of crawling but modify the approach for the bots when they are faced with a robot.txt file.

For example, some email scrappers may be created to target and source for Contact Us pages in various website’s robot.txt. Hence, more web owners utilise the function of Noindex as means of a preventive measure to ward off uninvited bots.

Website Architecture

Robots.txt files are also a good way for bots to understand and comprehend the lay of the land for the website. Good website architecture will have organised and labelled content, to improve its crawl efficiency and user experience. Having good information and navigation flow for your website benefits your digital robots and organic visitors.

Cornerstone articles are also a good feature to have on your website to help centralises your website’s content architecture.


Sitemaps are a list of URLs on your website that crawlers can use to discover and categorise your content. Google’s web crawlers utilise this as a method to understand your website better, judging it for its relevance and quality. A common practice for web owners is to submit your sitemap data directly through Google Search Console. It is commonly believed that submitting it through this way decreases a website’s chance of being neglected or wrongly interpreted by Google, giving it a better chance of being indexed.


A webpage can be redirected permanently or temporarily using status codes.

For permanent redirects, the 301 status code be used. A common tactic that can be utilised is through the use of 301 redirect codes to pass ‘Ranking Energy’ or ‘SEO juice’ from one web page to another. However, redirecting a ranked web page to another URL with a different content might get the website and web page penalised for its ranking factors.

302 status codes have the capability of temporarily moving a web page to a different URL. Think of it as a minor detour. Unlike 301 redirects, the SEO effects will be minimal, and temporary.

Search Engine Indexing

After scanning for the information, search engines have to process and store that information, and that’s where the indexing process comes into the picture. The index is where the discovered pages are stored, after being crawled and analysed.

Once your website has been successfully crawled, the next milestone would be for it to be indexed as well. Think of being indexed by Google as being accepted into a local prestigious college.

Indexing Errors may occur at times. Errors can come in the form of ‘not found’ errors, such as an Error404, or as a server error, with an error code in the 500s. Either way, indexing error can easily cause your website to be removed from the index, as it is a signal that Google picks up upon to infer that your website is not as healthy as its competitors.

However, much like how college offers can be withdrawn, indexed websites can still be removed as well.

Additionally, intentional removal from the index page is also possible with a website’s meta directives.

Relevant Read: How to Drive Relevant Traffic to Your Website via Google PPC

Meta Directives

Meta directives (or “meta tags”) are instructions you can show to search engines regarding how you want your web page to be treated.

There are many different meta directives that appear on indexing descriptions or tips and tricks as slang or terminologies. Here are a few common examples.

  • Noindex. With the use of “noindex,” you are communicating to crawlers that you want the page excluded from search results. Search engines index all pages as a default practice. Hence, the ‘noindex’ directive can be seen as a way of opting out.

    There are a couple of reasons to play the ‘noindex’ card on your website. For starters, profile pages are commonly non-indexed to prevent them from overflooding Google’s index of your site. This could overwhelm your web visitors when they search for your website on Google, or overshadow your other web pages.

  • follow/nofollow. These meta tags are also useful to tell search engines whether links on the page should be followed or not.

    Having a ‘follow’ will result in bots entering through your website and expanding its network of links through it. Employing the use of ‘nofollow’ however, allows your website to still be indexed (since it is not under a noindex meta tag), but prevents Google’s bots from overcomplicating your website by disallowing it to enter the metaphorical doors through these ‘nofollow’ links.

    “Follow” allows bots to follow through on the links on your page and passing link equity through to those URLs. Electing “nofollow,” will cause the search engines to not enter and pass through the links. By default, all pages usually have the “follow” attribute.
  • noarchive is used to restrict search engines from saving a cached copy of your web page. Caching a site is a common regular practice that search engines use to maintain visible copies of the page they indexed. By using a noarchive meta tag, you prevent an outdated version of your website from floating around on the internet.

    More commonly for sales or e-commerce platforms, noarchive tags are used to prevent information of your outdated website from surfacing on the internet. This can be helpful for hiding sensitive information such as outdated pricing, or a young unpolished version of your website.

Search Engine Ranking

Ranking is the final process of the search engines. In this final step, the indexed information is sorted and categorised under the different queries.

When a search is performed, in a matter of seconds, search engine flip through their index for highly relevant content and showcases it to the searcher, as a form of answer for their query. This is the purpose of search engines – to provide useful answers to searcher’s questions in the most efficient formats and most helpful way to display information.

At this stage, keywords are used to separate the content across the categories – first by parent keywords, then more specifically into subcategories of keywords. Like a library classifying all its books and reading materials, Google sorts them into topics based on commonly searched keywords. At least 500 million search queries are made on a daily basis, and it is reported that an average of 15% of all the queries submitted on Google Search are new and have never been seen before by Google. This shows how fast and how much keywords are rapidly changing, giving birth to new categories.

In terms of depth, search results are also ranked and differentiated by relevance and content quality. After all, a search engine’s purpose is to answer the searcher’s query. It would make sense for informative and problem-solving content to be rewarded by search engines and ranked higher on the list. To determine the relevance for websites to a certain query, search engines utilise their unique algorithm to understand websites and content better. Google’s algorithm is a common topic for discussion, as it is known to commonly undergo changes and updates. These adjustments are worthy of note as they affect the ranking of websites, depending on the metric which Google chooses to focus on, neglect or omit from their ranking process. Google’s Quality Guidelines can shed more light on websites who may have received an algorithm adjustment blow or boost.

All websites in the digital space are competing to rank higher. The higher a website is ranked, the more relevant their content is to the certain query. Rather, the more relevant their content is believed to be (by search engines). This is a powerful position that can be leveraged, as the first few results on a search engine result page gets most of the clicks. Many Google users would instinctively click on the first result on Google. Google even supports that notion, with its “I’m Feeling Lucky” button, a feature that allows the user to be taken directly to the first result of the results page, completely bypassing the need to decide on which number on the list to click.

What do Search Engines Want?

The focus and purpose of search engines have always remained the same. They serve to provide useful answers to searcher’s enquires in the most helpful formats.

But today, SEO now is much more different than in the past.

Over time, search engines get better at understanding the language and relationship between words and phrases. Eventually, as time passes, priorities are placed on different ranking factors, causing ranking positions to fluctuate from time to time, especially with each update to search engine websites.

Tips to Get Better Algorithm Impressions

  • Do not let anything slow down your website. A slow page frustrates users and creates a bad impression, chasing people away from your site. Page speed is vital to search engines, too. According to eConsultancy, 40% of people leaves sites that takes more than 3 seconds to load. Three seconds is a crazy short amount of time that makes or breaks it. This means that if your pages are slow, you are already losing customers. Plug-ins, picture size and widgets are common aspects that may challenge the site’s loading capabilities.

  • Write engaging content. Create content that can help someone and value-add to their experience or their life. With all the technical mumbo-jumbo and terminology, it is easy to forget that at its core, content is meant to be read by humans who live and breathe. Content that is valuable will gain its own momentum and traction of organic growth. Having relevant and updated content will also encourage other users to reference your content and use it as a form of resource. This attracts a crowd of interested audience members that are either buying more to your brand or can provide backlinks to you for free. Proper research and data analysis are also the foundation and essence of effective link building.

  • Do not neglect to put effort into creating unique and relevant meta descriptions for every page. Not only does this differentiate your content from you competitors, but it will also help enhance your SEO efforts as you start to gain brownie points with the algorithm. This effort will hopefully pay off in the form of improved or better ranking standings. Having these good digital habits also create a better image for your website, which can help attract clicks and views.
  • Enhance your content with a Call to Action. Include a call to action, or actionable instructions provides more tangible value to your readers, equipping them with the knowledge of what to do and an understanding of where they stand. Call to Action also helps you give your readers an avenue of joining you. Sometimes, a few customers might be unknowingly lost when they are hoping to reach your company or sign up but are unable to navigate or find out how.
  • Understand of your organisation and industry’s search landscape as much as possible. Knowing what your customers are searching for and how they are reaching your website is important in many aspects of marketing. It can help you generate content, know what type of value you can provide your customers, and take notice of your competitor’s actions. In some industries, there might even be cyclical movements or periodic spikes in the year. Knowing these points of time, this timeline will help you with planning your marketing campaign’s most optimal period.

Search Engine Optimisation

With constant changes made to the digital landmark, digital marketers around the world are challenged to think more analytically in their SEO efforts and approaches. While SEO does not have a steep learning curve, having more experience can allow you and your company to reap better results in a shorter period.

An experienced SEO agency will be able to view SEO as a digital tool and resource, that is essential to a company’s success, rather than just a channel or department. This is the inherent benefit of outsourcing your digital marketing needs.


Understanding the search engine process is the first step to understanding SEO better.

All of these search engine work, coincide to form the search engine process. Search engine processes are constantly updating and renewing, which explains why SEO is no easy task for any industry. Keeping up with algorithm changes and understanding the game is key to a good digital marketing strategy.

Here at Leading Solution, we provide a range of digital marketing services:

  • Search Engine Optimisation (SEO). Our strongest asset has always been in SEO. With the ever-changing SEO algorithm, past well-optimized websites can be outdated very quickly.
  • Website Design & Development. Having a sleek, powerful website increases conversion. Our websites are SEO-friendly, mobile responsive and optimised for fast loading time.
  • Pay Per Click. PPC campaign drives targeted and ready buyers to your website almost immediately.
  • Social Media Marketing. Social media marketing is great leverage to out your company in front of thousands of highly qualified prospects.
  • Content Marketing. With search engines placing heavy emphasis on quality content, content writing is increasingly important in the digital world.
  • Email Marketing. Email marketing is still one of the most effective tactics for attracting new customers and retaining customer relations.
  • Lead Generation. Highly-targeted leads for your marketing funnel.