What is SEO and How it Works
(Simple and Easy Explanation)

SEO, or search engine optimisation, is the process of enhancing your website to rank higher on search engines, thereby driving more traffic. Similar to ensuring a shop in Singapore's busy streets stands out, you want your online "storefront" to be easily found. By optimizing for relevant keywords, ensuring your website is user-friendly, and providing valuable content, search engines like Google will prioritize your site in their results.

In the competitive digital landscape of Singapore, some might choose to invest in SEM (Search Engine Marketing) for immediate visibility. However, SEO Singapore offers organic growth, building a foundation for long-term online success.

What is SEO and How it Works - Digitrio

What is SEO

SEO stands for Search Engine optimisation. The primary components of SEO include:

  1. 1
    Keywords: Specific terms or phrases users search for.
  2. 2
    Accessibility: Ensuring a website can be easily accessed and understood by search engines.
  3. 3
    Relevancy: Providing content that matches the intent of search queries.
  4. 4
    Authority: Building trust and credibility in the eyes of search engines.

Dive Deeper: To master SEO, it's essential to grasp how search engines operate. For a deeper dive into SEO, click here.

How does Search Engine Works - Digitrio

How Does Search Engine Works?

As Google is the most dominant search engine in Singapore, most of this guide will focus on the Google search engine.

Here are the three functions through which Google search engines primarily work.

  • Crawling
    Search engine bots will scour the internet for new content. It crawls from one page to another, following the links placed on each page, and adding any new content it finds to its index.
  • Indexing
    Search engines save and filter the content that has been found. Once a web page is put into the index, it can now be displayed in search results.
  • Ranking
    This is where search engines rank content based on how relevant it is to the user’s search query.

In a nutshell, you are searching through Google's index of websites and not the entire Internet when you google. This is an important concept to understand when it comes to optimizing the accessibility of your website, which will be covered more later on in the article.

Is Your Website SEO Friendly?

Pricing Icon2

How Does SEO Work?

SEO, or Search Engine optimisation works by:

  1. 1
    Researching and understanding the keywords your target audience uses.
  2. 2
    Ensuring your site is easily accessible to Google bots
  3. 3
    Optimizing content so that it's both helpful and aligns with users' search queries.
  4. 4
    Establishing authority through links from other sites, or more recently, as defined by Google,  E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness)
How does SEO Works - Digitrio

What is Google Algorithms

What is Google Algorithms

The Google search algorithm is a complex system that allows Google to find, rank, and return the most relevant pages for any given search query.  Google employs over 200 ranking factors in its algorithm.  Google update their algorithms roughly 500 to 600 times each year to ensure that they are still ahead of other search engines like Bing and others. 

One of the most notable algorithms that has solidified Google's position as the largest and most widely used search engine in the world is PageRank.

Google was initially named ``BackRub`` for its analysis of the web “backlinks”

What Is Google PageRank?

Google PageRank is a link analysis algorithm that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. It is what makes Google become popular due to its accuracy in returning search results when it first came up in 1998.


Google Panda Update

Google's Panda monitors the content quality of the website. A website that has non-informative content that is not unique and simply repeated from other websites would rank lower than one with useful content that is unique and differentiated. Pages with sufficient content to be useful and high quality external links have a boost under the Panda algorithm. On the other hand, pages with thin content and high bounce rates would suffer.


Google Penguin Update

Google's penguin considers the quality of backlinks to assess the authority of a website. Sites with poor quality links were penalised, while sites with backlinks from high authority websites in a niche related to theirs got a boost. It also looks at anchor text that captures the attention of readers and accurately describes the link. Posting “Click here” or the website URL itself repeatedly would result in a drop under Penguin.


Google Hummingbird Update

Google's hummingbird algorithm makes use of semantic search and Google Knowledge Graph. It essentially associates knowledge that users are most likely looking with certain search queries using machine learning. For example, a person typing in “pizza recipe” may also be looking for calorie content and cooking time. Hummingbird essentially associated this information together so that the cooking time and calorie information would also come up for a user searching for recipes. Guides, articles with deep analysis and tutorials got a boost under Hummingbird since they were able to provide extremely relevant content to a specific target audience, even if they weren’t typing in that search query directly.

Google algorithm updates can sometimes pose a headache to website owners, but this is something that Google will continue to do as part of its mission to organize the world’s information and make it universally accessible and useful and you can keep up with the major Google algorithms update here.

Google Icon

Google’s Mission is to Organize the World’s Information and make it Universally Accessible and Useful.

SEO Pillars

To truly understand SEO and how it works, we can break it into these 4 main pillars that make up the proven SEO strategy that Digitrio uses. 


Keywords SEO Pillar

Keywords are the foundation when it comes to SEO and the type of keyword and the quality of the keywords you target play a big role in the outcome of your SEO efforts.

We want to be targeting keywords that your targeted audiences are most commonly using to search for and below are 4 keys areas we mainly want to look into for quality keywords in SEO:

  1. Type of Search Intent
  2. Average Monthly Searches of the Keywords
  3. Commercial Values of the Keywords
  4. The difficulty of the keywords relative to your website

You can get the above data using a keyword research tool like Ahrefs or via your own Google search console to identify what keywords you are ranking quite well but not quite there yet.

1. Search Intent

Search intent is about what is the primary goal a user has when searching a query in the search engine, Google. We can classify the search intent into 3 main groups:

  • Navigational
  • Informational
  • Transactional

Understanding this is key as it allows us to make sure we are targeting the right pages to deliver the right search intent, thus able to provide useful information mentioned in the steps to a Google-friendly site from Google.


Navigational intent is keywords used when the user already knows the website that they want to go to. For example, when someone types in the name of a particular company or brand along with the specific product or service, they have the intent to access relevant pages about that company or brand.

Eg, Users will type “Digitrio” or “Digitrio SEO services” to visit our homepage or our SEO services page.

(*This type of search query, we often do not target for SEO, as we are most likely already ranking high for our own brand keywords)


Informational intent is keywords used when users are primarily looking to gain knowledge about a particular topic. These types of keywords have a large volume of traffic, but users aren’t necessarily looking to buy anything. However, ranking for informational keywords can still be valuable as you can direct people to other quality content on your website that may be more transactional in nature.

Eg, Users will type “Benefits of SEO” or “SEO vs SEM” to learn more about these topics.


Transactional intent is keywords used when the users show clear intent to buy a product or service in the near term. These types of keywords are the most fierce in competition as most of your competitors will be targeting in their SEO to rank for it.

Eg, Users will type “SEO Singapore” or “SEO services” to find an agency that they can engage for the services.


2. Average Monthly Search Volume

We want to make sure that we are doing SEO on keywords that have a good search volume per month else there is not much point in getting on Page 1 for keywords that your target audience does not use.

Use tools like Google keywords planner or Ubbersuggest to find out if the keywords chosen are being searched by your targeted audience.

Eg, if you are in the automobile industry, you will want to target “used car Singapore” instead of “pre owned vehicles Singapore” as even though both keywords invoke the same intent as only one has a lot more significant searches volume per month used vs nil.

SEO Keyword Term - Search Volume

3. Commercial Values of the Keywords

It is good if the keywords have a lot of search volume per month but does the keywords drive conversion? One of the ways to judge it is via Google keywords planner’s – “Top of Page Bid”. This is Google’s estimate of how much an advertiser generally spends for a single click of that keyword.

Top of Page Bid CPC

Informational keywords generally have a lower top of the page bid CPC, but they might have significant search volumes.

As such, we define the commercial values of the keywords with a simple formula below:

Commercial Value = Avg Monthly Search Volume * Top of Page Bid CPC


4. Difficulty of the Keywords

The first 3 points are definitely important factors when comes to keywords, but the difficulty of the keywords are crucial among all of them. After all, if we are not able to compete in it and rank in Google’s organic search results – Page 1, we do not get to enjoy the fruit of the labours SEO. (More Traffic & Conversions to your website)

The keyword’s difficulty is based on a number of different factors, including domain authority, page authority, and content quality but that is relative to your website and pages.

Eg, if you are Amazon.com, most keywords are within your range of the target for SEO vs if your website is new whereas not as authoritative as Amazon.com.

SEO Keywords Difficulty


Accessibility SEO Pillar

Accessibility is about making sure that your site architecture is in a logical link structure that allows ease of Google to crawl & index it so as to better understand what your site is about.

Below are the 4 main pointers that will allow search engines to better access your website.

  1. Organized Site Structure
  2. No Website Errors
  3. Google Page Experience
  4. Internal Linking
Organized Site Structure

1. Organized Site Structure

Site structure is how the pages on your website are organized. It is important to be in an organized manner that is flat and well inter-linked.In other words: your site’s pages should all be only a few links away from one another.

This will allow Google to be able to crawl 100% of your site’s ages and able to index them well as that is one of the key parts of the accessibility pillar of SEO.

2. No Major Website Errors

Website errors are pages shown to visitors when something goes wrong when landing on the page. These are bad for SEO purposes because Google can’t crawl or index the page, and also hurts the user experience.

Technical errors like 301, 302, 404, and 500 should be fixed so that Google can crawl the website.

404 Error - Page Not Found

3. Google Page Experience

Google Page Experience is a measurement by Google on how well is the user experience when engaging with your website. It looks at the following metrics:

  • Core Web Vitals (Loading, Interactivity & Visual Stability)
  • Mobile Friendliness of the Website
  • Safe Browsing (If there is any malware or unsafe script on the website)
  • HTTPS (Secure browsing that contributes to another aspect of safe browsing)
  • No Intrusive Interstitials (No Popup Ads that block most or all the pages)

Great user experience is a key factor that Google consider when it comes to search engine optimisation (SEO) especially this is one of the rare updates by Google that is transparent and more open about these ranking factors and provides useful tips for improving scores.

Google Page Experience

4. Internal Linking

Internal linking is the use of links that direct the user from one page on your own site to a different page on the same site. These links stay within your website. For example, there may be an internal link directing traffic from the “Home Page” to the “Contact Us” page.

One key benefit of internal linking is that it helps with the “finding” of this page by Google bots which will further help with the accessibility and it is especially important for pages you are targeting for SEO.

Here are some other ways that your site can benefit from internal linking:

  • Establishes an information hierarchy on the site, thus improving your site architecture
  • Spreads link equity around the site. Link equity is a Google search engine ranking factor where the links pass authority and value from one page to another. Links that pass equity through link building are used to help determine where you rank on the search results.
  • Internal pages on the website can be linked to SEO pages so that Google can easily identify what keywords the SEO page is optimized for.
  • Allow visitors to navigate a website and learn more about what you have to offer


Relevancy SEO Pillar

Relevancy is about how optimizing your webpage content to make sure it provides useful information based on the keywords entered by the searchers. It is one of the many on-site SEO factors that search engines consider is how relevant the content on the page is to the organic search term or topic.

There are many ways that search engines like Google will evaluate the site content relevance.

  1. Meta Title & Description
  2. SEO-Friendly URL
  3. Header 1, Header 2, and Header 3 & Etc
  4. Content Matches Search Intent

1. Meta Title and Meta Description

The title tag (meta title) and meta description are foundational pieces to your search engine optimisation. They must contain keywords relevant to the content of the page. These meta tags help search engines analyze the page and index them according to relevant keyword phrases. After performing your keyword research, it’s important to incorporate the desired keyword phrase into the meta title and description.

The title also provides visitors with an insight into what the content on that page is about. In addition, the meta description is the words below the title in the search results that inform the reader about the page and get them interested enough to click.

Here are some guidelines to follow:

  • The title tag should contain less than 70 characters and should incorporate keywords
  • Google and other search engines recommend including your brand in the title, but have them separated from the rest of the title using a colon, pipe, or hyphen.
  • Meta descriptions should be between 150 to 160 characters long so that the entire tag fits on the search results page.
  • The description should also target a unique keyword but avoid keyword spamming.
  • The meta description should engage traffic visitors and entice them to click on the link.
  • Consider what the audience from the organic traffic is looking for. Provide words that provide a value proposition such as “Free” or “Voted #1 brand.” In addition, you can include action verbs like “Book Today,” “Shop Now,” or “Read More.”

In addition, you can add structured data so that search engines can better understand what’s on your site. Structured data is a code added to your site’s pages to describe the content contained on the page.

2. SEO-friendly URL

Along with the content, anchor text, title tag, and meta description, search engines will look at your URL to understand what your content is about. An SEO-friendly URL is designed to meet the needs of searchers. Ideally, it should contain the keyword you’re targeting based on your keyword research.

Use hyphens in between words to let the search engine know where each word separates. Also, make the URL short so that Google can easily decipher what the topic of the page is about. In fact, short URLs tend to rank higher on the search results page than long URLs.

3. Header 1, Header 2, and Header 3 & Etc

Search engines work to understand your content so that they can provide the most relevant pages to users. Heading tags are elements from an HTML code allowing you to structure your content on web pages. There are 6 HTML tags: H1, H2, H3, H4, H5, and H6. Each tag corresponds to a ranking level where H1 is the most important and H6 is the least important. Just like the other title tag and meta description, make sure to include your target keyword phrase from your keyword research in some of your headers.

Heading tags have a few benefits:

  • They allow traffic visitors to glance at the content map and directly read the section that interests them.
  • Headings allow the writer to structure their ideas.
  • Search engines can easily identify the difference between headings and content text blocks, enabling them to comprehend your page better.
On Page SEO

4. Content Matches Intent

Search intent is the goal that a user has when they’re typing their query. Search engines will rank pages higher if their content matches the user’s search intent. For example, a user looking for a pizza recipe has a different search intent than someone looking for takeaway pizza.

If users find what they’re looking for on the site, they’re less likely to bounce and return to Google within seconds. Thus, if your content matches the search intent, you’ll see low bounce rates.

One way to see the best type of content that matches the search intent is to do a Google search of the keyword and read the content of the top websites on page 1 to get a sense of the intent and from there optimize your content on the page to make sure it provides the answer that the searchers are looking for.


Authority SEO Pillar

Authority is about optimizing your website to be more trustworthy to Google through acquiring links.

Search engines want to provide users with reliable and credible information and one of the ways, they use to identify it is if other websites link to you. Google interprets a link from site A to page B as a vote by page A for page B. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.”

Below are 3 factors search engines like Google consider:

  1. Quantity of Links
  2. Quality of Links
  3. Anchor Text

You can know what page on your site has links by viewing that information in the Google search console or using a 3rd party tools like Ahrefs.

1. Quantity of Links

As mentioned above, search engines like Google view links as “votes” as such one of the important factors in authority is the number of links.

Eg. If site A has 1000 links and site B has 100 links, site A is more authoritative in the eye of search engine optimisation. (If we just compare on the number of links only)

But another key factor is the quality of links, thus it is important to have a high quantity of quality links vs just going after pure quantity.

2. Quality of Links

Quality of links is how search engines measure if the links are relevant and from a trusted website.

Eg, A link from Amazon.com definitely carries more weight than 1 from an unknown website.

Search engines are able to recognize relevance, intent, and linking patterns. Instead of focusing on acquiring links from every source possible, we should acquire links from trusted sources that are of the following:

  • Same Niche as your website (The same category of the website, Eg If you are in the dentist industry, it is best to acquire a link from a health-related website)
  • High Domain Rating (SEO tools from Ahrefs that measure the authority of the website)
  • Great Organic Traffic from the site (If the link from the site, have great organic traffic – not only do we get referral traffic from it but it is also a good sign that the site is trusted since they are able to have traffic from Google itself and is ranking on Page 1.

3. Anchor Text

Anchor text is the visible, clickable text in a link. As covered above, the quantity and quality of links are keys but what is the text used to link in a.ka anchor text are equally important.

Search engines use anchor text as a reflection of how other people view your page — and by extension, what your pages might be about. It is important in search engine optimisation that the anchor text ratio is natural.

Eg, if your website suddenly acquires 100 links of “SEO services” anchor text – that is a sign that you are engaging in spammy activities which then will affect badly your ranking and SEO.

Anchor text can be categorized into the following:

  • Exact Match (Contain what your SEO keywords are about)
  • Partial Match (Partial match what your SEO keywords are about)
  • Brand (Company name or variation of Company)
  • Natural (“click here” or “learn more” are an example of it.)
What is Anchor Text

SEO (search engine optimisation) and how it works can ultimately be boiled down to just Keywords, Accessibility, Relevancy, and Authority. These few key fundamental concepts are evergreen and are unlikely to change in many years.

But SEO is constantly changing, and even though these 4 SEO pillar concepts will still stand true, what will be changing is how Google evaluate it. Eg, they have just recently added core web vitals in their Google Page Experience to further refine how they define the accessibility part and there are a lot of benefits to doing SEO for your business.

To have a quick understanding of how your website is performing, try our FREE SEO audit tool and contact us – should you require our SEO services to help to make your website rank better for SEO for more Traffic growth.

Traditional and Technical Explanation of SEO

At its core, Search Engine optimisation (SEO) can be broken down into three foundational pillars:

  1. Technical SEO
  2. On-Page SEO
  3. Off-Page SEO

Technical SEO

Technical SEO Banner

Technical SEO mainly focuses on the way Google crawls pages. It does so behind the scenes, with important elements such as meta descriptions and keywords. This makes your site very fast and relevant for search engines that can easily crawl it.

Why Is Technical SEO Important?

Why do you want to prioritize technical SEO? Well, technical SEO is what allows search engines like Google to know that you have a website of high value. You should engage in Technical SEO because it allows you to be found easily and increases your chances of higher rankings. For example, it could provide information about your company and its respective products.

If Google prioritized webpages that was slow, non-responsive or confusing to navigate, Google users would be more likely to take their search queries somewhere else. So if your website loads quickly, has no dead links and is secure, Google’s crawlers will give it an extra boost in search rankings.

The reasons for this are evident. Creating a strong technical foundation for your website will go a long way in satisfying and delighting your users. Search engine crawlers take notice and prioritize your website over others who offer slower and buggier experiences.

What Technical SEO Ranking factors Should You Take Note of?

Critical considerations for technical SEO include:

  • Domain age
  • Domain strength
  • No plagiarized content
  • URL structure
  • No dash domains
  • 301 redirects
  • Canonicalization
  • Website speed
  • Mobile-friendliness
  • Site navigation

On-Page SEO

On-Page SEO Banner

On-page SEO (also known as “on-site SEO”) is the practice of optimizing web page content for search engines and users. Common on-page SEO practices include optimizing title tags, content, internal links and URLs.

This is different from off-page SEO, which is optimizing for signals that happen off of your website (for example, backlinks).

Why is On-Page SEO Important?

The majority of today’s search engine optimisation work focuses on on-page SEO. The reason for this is that Google and other search engines like to focus primarily on content and meaning.

SEO is not just about keywords and link building anymore. It’s all about providing a great user experience, which leads to higher rankings in the SERPs (Search Engine Result Pages) and content play an important part of it.

It’s important to optimize your website not only for users but also for Google, as it is one of the most used search engines nowadays – over 90% of its users use Google as their primary search engine.

What On-Page SEO Ranking factors Should You Take Note of?

Critical considerations for On-Page SEO include:

  • URL
  • Title tag
  • Meta description
  • Heading tags
  • Alt tags
  • Keywords
  • Content
  • Internal linking
  • Images

Off-Page SEO

Off-Page SEO Banner

“Off-page SEO” (also called “off-site SEO”) is when you do things outside your website to impact your rankings in SERPs, like with on-page SEO.

Optimizing for off-site ranking factors involves improving search engine and user perception of a site’s popularity, relevance, trustworthiness, and authority. This is done in a number of different ways. For example, by other reputable websites/blogs/individuals linking to your website and giving it good reviews, “vouching” for the quality of your content.

Why is Off-Page SEO Important?

Off-page SEO is important because it can increase organic search rankings and traffic to a website. By implementing off-page SEO efforts, website owners can build links and social media mentions that point to their site. These links and mentions help to indicate that the site has credibility and authority, which improve the site’s rankings on organic search results pages.

There are many search algorithms and ranking factors, but SEO experts argue that the relevance, trustworthiness, and authority of sites affect their rank and off-page SEO play an important in achieving that.

What Off-Page SEO Ranking factors Should You Take Note of?

Building backlinks is critical for off-page SEO to rank well in search engines. This means that a site with many high value backlinks should rank higher than an otherwise similar one without as many.

Critical considerations for Off-Page SEO include:

Understanding SEO Through Infographics

SEO infographics are powerful tools that visually simplify and enhance the understanding of key concepts in search engine optimisation. This example showcases two distinct infographics:

What is SEO & How it Works Infographic

This infographic breaks down the concept of SEO, simplifying it into key components: Keywords, Accessibility, Relevancy, and Authority.

What is SEO and How it Works Infographic

Website Redesign SEO Checklist Infographic

This infographic is a checklist of the different stages of a website redesign and what to take note of to not only maintain but also boost your SEO.

Website Redesign SEO Checklist Infographic

Google Penguin 4.0 Update Infographic

This infographic details the Google Penguin 4.0 update, introducing real-time penalties and rewards for link quality on specific pages.

Google Penguin 4.0 Update 2016