Google generates over 1.2 trillion searches each year.

Do you want a piece of that traffic? Do you want those potential customers to find your website?

If you want to generate leads and sales online, you need to understand how search engines work — it’s critical to creating a successful search engine optimization (SEO) strategy.

What is a search engine?

Popular search engines like Google, Bing, Yahoo, and even Amazon are websites that help searchers find information. That information is contained in a database (in this case, a database of trillions of web pages). That database is combed through by search engine algorithms, which the right information for each searcher, and then deliver them on search engine results pages (SERPs) in order of quality and relevance.

How do search engines work?

When a searcher types a search query into a search engine, that search engine searches through the database, finds relevant web pages related to the search terms that were entered, and serves them to the searcher on a search engine results page. The image shows the first page of a SERP for the query “what is a search engine.”

A search engine results page for "what is a search engine?"

Search engines are constantly evaluating old and new content on the world wide web to figure out exactly what information needs to be in their database, how that information should be ranked, what relevant content is available for a search, and then the order that information should be presented whenever someone searches for something.

The goal is to provide the best user experience possible for the searcher. Search engines want their users to find what they’re looking for as quickly as possible.

A series of factors called ranking factors are used to decide the exact order that content should be served to someone for each unique search. Search engine ranking signals include:

  • How fast the webpage loads
  • If the page contains high-quality content
  • What searchers are intending to find when they search for something
  • How many links from other websites point to this webpage (more links indicate that the web page has more authority—the writers/creators know what they’re talking about)

To do this, search engines use computer programs called crawlers to explore existing websites for new content and to search for new websites. When new web pages are found, they’re added to the search engine’s database—this is called indexing.

When existing websites are recrawled, their information is updated in the database. This is called reindexing. Each website has a crawl budget, which is how many pages on your website a search engine will crawl/recrawl each day.

Existing pages can also help web crawlers to find new content. When internal links on an existing page (links from one page on your website to another page on your website) are added, crawlers that are recrawling your web pages to see how the content has changed (or not changed) will follow those links to explore the new content on your website.

The process can be broken down into a more complex series of actions beyond crawling, indexing, and reindexing. The image shows the exact process:

Diagram showing how search engines work.

For a new page, a crawler must first find it. Once it has been found, the scheduler decides how important this content is (in terms of what a searcher might be looking for) and then decides when to crawl the content (and how often to crawl it again to check to see if the content has been updated).

In an in-between step, the crawler first transfers the new web pages to something called a parser (this happens between crawling and indexing). The parser examines links, content, and other information, and then indexes the web page (if it decides that it should be indexed).

If the web page is then indexed, it’s ready to be served to a searcher.

This same process is repeated for existing content so that it can be updated in the index and reevaluated to learn more on what the content is about if it’s changed.

What is a search algorithm?

A search algorithm is a set of programmatic steps that the search engine follows to evaluate all the content in a search engine’s index. Then it decides, according to a set of criteria, how that content should be ranked and delivered for every search that someone types into a search engine, with the ultimate goal of serving most relevant results to the searcher.

How the Google search algorithm works

When you hear about Google’s algorithm, what’s actually being talked about is a series of algorithms that evaluate thousands of factors on a web page. For example, one of Google’s algorithms is called PageRank. It focuses on evaluating backlinks and uses this information, along with the information that the other algorithms evaluate, to decide how to rank a page.

Another algorithm called Hummingbird uses, among other things, machine learning to help Google better understand what a search query is looking for so that the best content can be served to the searcher.

The Google algorithms work together to apply all the different ranking signals so that the searcher gets the best content possible. According to Google, there are some major ranking factors that matter more than most others.

Google ranking factors

It’s estimated that Google has between 200 and 10,000 ranking factors. Here are some of the most important.

Content relevance

When Google tries to understand what a page is about and how that page compares to what a searcher is looking for, it looks at the keywords contained in the search query.

Keywords are important to Google because they’re indicators of a topic. For example, if someone searches for, “What are the major breeds of dogs?” then Google is going to look for those keywords in potential results.

A SERP that shows results for "what are the major breeds of dog?"

You can see in this SERP that the exact keyword phrase doesn’t show up. In fact, even the word “major,” doesn’t show up.

However, the topics of the articles are relevant to what’s been searched, and some pieces of the keyword phrase show up. Each result is about dog breeds. While one result doesn’t include the words “dog breeds,” and instead says, “groups of dogs,” Google still serves this result because it understands that, in this case, the content is relevant to the topic. It understands that a group of dogs and dog breeds are similar, or at least related.

You’ll notice also in the SERP that several of the results are relatively recent — from late 2019. Another ranking factor that Google uses is the freshness or recency of content. It doesn’t want to serve content that is too old unless that content is “evergreen,” which refers to content that doesn’t need to change over time to maintain value (an article on “how to tie a tie” is an example of an evergreen piece of content that would not need to be updated over the years to be valuable).

While several of the articles are recent, several others are likely not. That’s because, for this search query, the content doesn’t have to be recent because the major dog breeds likely don’t change much over time.

However, if someone searches for, “The best dog breeds of 2021,” the results will be different:

A SERP for "best dog breeds of 2021."

The results from 2019 no longer show up because Google understands that those pieces of content aren’t relevant to the search. It provides more recent content because of the keyword, “2021.”

Relevance is only one part of the equation. Content that is relevant but is low quality isn’t going to rank.

Content quality

High-quality content gives the user what they want and answers their question fully and completely. This is why so many top results are over 2,000 words — it takes a lot of writing/information to answer a question comprehensively.

To determine if content is quality enough to serve to a searcher, the search engines consider search intent, which is what a user is looking for.

For example, someone who types in, “what is the sky made of,” wants a question answered. Someone who types in, “best TVs in 2021,” likely wants to make a purchase. There are other types of search intent. Someone who types in, “videos of Warframe,” wants to see a specific type of content.

The quality of the content must then match up with search intent. High-quality content is comprehensive without having fluff.

One way that Google determines if content is high quality is by considering EAT — expertise, authority, and trust.

  • Expertise is determined by the quality of the content and how well it matches up with a search query. Expertise is something you demonstrate, not something you claim. It’s good if you’re a recognized authority on a topic, but it’s the content itself that demonstrates you know what you’re talking about.
  • Authority, on the other hand, is about your reputation. This can be demonstrated by links to your website from high-quality sources (think links similar to the ones Wikipedia has), but it also comes from things like reviews of a website/writer/content creator or even news articles about the website/creator. Links, news, good reviews — these demonstrate to Google that your content is probably good enough to serve to a searcher.
  • Trust is demonstrated by other pages on your website and pages that you link to. Your content is trustworthy if it’s clear who created it, if the website has clear contact information, and if the content has high-quality sources. Trust is also demonstrated by backlinks. If people are linking to you, this is a signal that you are a trustworthy source.

Ease of use

Usability is all about making a website as easy for a searcher to use as possible. This means you have clear organization, like a menu that can be easily navigated. It means that you have headers in your content that break your web pages into easily digestible sections. It means your site structure is simple and easy for users to understand. The image shows a simple site structure.

A diagram showing a simple website structure.

Ease of use applies in other ways as well, including in technical SEO.

  • You should have internal links throughout your content so that visitors can find related pieces of content easily.
  • You should have SEO-friendly URLs that include keywords and are short, so that they look simple to users and so that their topic is clear to a search engine.
  • Page speed is huge as 37% of visitors bounce when your site takes five seconds or more to load.
  • The language you use should be appropriate to the subject matter. Filling your content with difficult-to-understand words or overly complex sentences can make your content harder to use.
  • Your website needs to be mobile-friendly, which means that it can be viewed at any screen size without the user having to zoom in or out to consume the content.


Your goal should always be to make your content as accessible to users as possible, but it should also be accessible to search engines. For example, it should have an XML sitemap, which tells a crawler what pages exist on a website.

XML sitemap of the Granwehr site showing links to all pages.

You’ll also want a robots.txt file, which tells search engines which content to crawl and which content to ignore. For example, you might not want a search engine to index a page on your website that includes paid content. Otherwise, it might end up available for free online.

Crawlers use internal links to find other pieces of content, so you’ll want to include links from old pieces of content to new pieces of content and vice versa.

If you have duplicate content on your website, you need to tell search engines which piece of content to index and which piece to ignore. Canonical tags do just that.

What is SEO and why is it important?

SEO (search engine optimization) is a digital marketing strategy that focuses on optimizing page content on your website for a search engine. Webmasters take each piece of content — from their homepage to their blog and everything in between — considers the search engine’s ranking signals, then do their best to ensure that content follows the search engine’s guidelines and satisfies those ranking signals.

The best SEO is done from the ground up. Webmasters usually create content with a user’s query in mind. They use keyword research tools to learn what a user’s search might be. They then create the content —  rather than creating the content first and then trying to fit the content to the search engine’s ranking signals.

Then, they evaluate how well that content is performing using tools like Google Search Console. They then make changes to the content as necessary to make their content more likely to rank.

Essentially, SEO is about creating content that someone wants to consume, then taking specific actions to ensure search engines understand what that content is and why it’s valuable so that they’re more likely to serve it to that person.

SEO is important because businesses of all types, from global e-commerce stores to small businesses with a single brick-and-mortar location, want to show up on a search engine when someone is looking for a product or service they offer.

Nearly 93% of all global traffic comes from Google search, Google images, and Google Maps. Higher search engine rankings correlate to more traffic to your website, and more traffic means more potential customers. If you want to use search engines to make sales, you need to not just create content, but to optimize it. That’s why you need SEO.

Get a complimentary SEO audit

Now that you have a better understanding of how search engines work, you’ll be able to create content that better satisfies searchers, that search engines are more likely to serve to those searchers, and ultimately, you’ll be able to increase traffic to your website, increasing the chance for more conversions and more sales.

Want to see how you’re doing with SEO? Get an instant SEO audit below. Or, schedule a free consultation to see how intent SEO can boost search traffic revenue by 700%.