Search Engine Optimisation (SEO) is one of the most important parts of digital marketing. It is the process of improving your website so that it appears more prominently in search engine results pages, often called SERPs. When someone searches on Google, Bing or another search engine, SEO helps your website to be one of the top results they see.

For many businesses, SEO can be the difference between a potential customer finding them or finding a competitor. However, for beginners, the language of SEO can feel like a foreign dictionary. To help you get started, this article introduces the key concepts and terminology you need to know. We’ll go into detail in terms of how you can start to put your knowledge into practice in further articles. For now, it’s just important to know what certain terms mean.

What is SEO and how do I measure it?

SEO stands for “Search Engine Optimisation”. It’s about making your website as attractive as possible to search engines while also providing a good experience for real users. It involves a combination of technical improvements, content creation, and building authority across the internet. The ultimate goal is to increase the amount of relevant traffic to your website without paying for ads. This is known as organic traffic.

GA4

In GA4, traffic from SEO will be defined as “Organic Search” in your default channel groupings. This is one of the places you can measure the success of your SEO. Another place you can do this, at a more granular level, is Google Search Console.

Google Search Console

Google Search Console (often shortened to GSC) is a free tool provided by Google that helps you understand how your website performs in search results. While GA4 shows you how much traffic comes from organic search, Search Console goes deeper by showing you what people are actually searching for before they click on your site.

With GSC, you can:

• See the search queries that bring people to your website.
• Track your website’s average position in Google’s search results.
• Find out how many times your site has appeared (impressions) and how many clicks it has received.
• Identify which pages are performing well and which need improvement.
• Spot any technical issues that might stop Google from properly indexing your pages.

For beginners, one of the most useful features is the Performance report (“Search Results” down the left side). This shows you a breakdown of queries, clicks, impressions, and click-through rates (CTR). By reviewing this data regularly, you can spot opportunities, such as keywords you are already ranking for but not yet in the top positions. Creating or improving content around those queries can quickly lead to better visibility.

Google Search Console is an essential companion to GA4. While GA4 helps you measure traffic and behaviour, GSC helps you understand how search engines see your site and where you can make improvements.

Key SEO terminology

Keywords

Keywords are the words and phrases people type into search engines when they are looking for information. For example, if someone searches for “coffee shops Belfast”, the keyword phrase is exactly that. By understanding what your audience is searching for, you can create content around those keywords so your website has a better chance of appearing in the results.

There are different types of keywords:

• Short-tail keywords: one or two words, broad and competitive (for example, “shoes”).

• Long-tail keywords: longer, more specific phrases (for example, “women’s running shoes for flat feet”). These usually have less competition and can bring more targeted visitors.

Why are keywords called “long tail” and “short tail”?

The terms long tail and short tail describe the shape of a graph that shows how often different types of keywords are searched.

In a graph of search demand, short-tail keywords are the broad, popular search terms at the top. They are searched very frequently, but because of this, they are also very competitive. For example, “trainers” or “holidays” would be short-tail keywords.

As you move along the graph, the search terms become longer and more specific. These are the long-tail keywords. Individually, they are searched less often, but there are a huge number of them, which creates a “long tail” shape on the graph. For example, “best trainers for running on concrete” or “family holidays in Spain with toddlers” are long-tail keywords.

Long-tail keywords are valuable because they usually bring more targeted visitors who are closer to making a decision. Someone searching “shoes” could be looking for anything, but someone searching “women’s waterproof hiking boots size 6” is probably ready to buy.

On-page SEO

On-page SEO refers to everything you do on your actual website to help search engines understand and rank your content. This includes:

• Writing high-quality content around your keywords.
• Using headings (H1, H2, etc.) properly and in the right order (e.g. H1 then H2, H3.. not H2 then H1)
• Adding descriptive title tags and meta descriptions (note: Only Meta titles are SEO ranking factors, Meta descriptions, however, help improve your click-through-rate once on the SERP)
• Structuring URLs clearly (don’t use special characters e.g. ‘&,_,’ and don’t make them too long)
• Adding internal links to other pages on your site. (linking text to related other content on your site, like this)

On-page SEO is about making your website clear, relevant and easy to navigate for both users and search engines.

Off-page SEO

Off-page SEO is about what happens away from your website that affects how search engines see your site. One of the biggest forms of off-page SEO is backlinks.

Backlinks are links from other websites pointing to your site. When high-quality, trustworthy websites link to your content, search engines treat this as a vote of confidence. The more credible links you earn, the more authority your website builds.

Authority score

Authority Score is a rank on a scale of 1-100 and is a way of measuring how trustworthy and influential a website is in the eyes of search engines. It is not a number that Google itself provides, but rather a metric created by SEO tools to help you understand the overall strength of a website. In fact, it was coined by an SEO business called Moz.

A higher Authority Score usually means a site is seen as more reliable and respected. This is often based on things like the quality and number of backlinks (links from other sites), how popular the site is, and how well it performs overall. For example, a well-established news website or a government site would have a higher Authority Score than a brand-new personal blog.

For SEO, Authority Score is useful because it gives you an idea of how difficult it might be to compete with another site. If a site with a very high score is ranking for a keyword you want, it may be harder to outrank them. On the other hand, targeting keywords where competing sites have lower scores could give you a better chance.

In simple terms, think of Authority Score as a measure of a site’s reputation online. The stronger the reputation, the more weight search engines give it.

Understanding Authority Score comes in handy when it comes to backlink and internal linking strategies. For backlinking, you’re only as strong as the ones you surround yourself with. So, gaining a heap of low-quality backlinks can often lead to you yourself also having a low Authority Score.

In terms of internal linking, your “Page authority” can be shared between pages. A certain amount of authority will pass through each link to another page. This is often referred to as a “the sneeze effect” where “link juice” is passed from one page to another.

But, that’s a concept we can cover in full in another article! For now, you just need to understand the basic concept of Authority Score.

Technical SEO

Technical SEO focuses on the behind-the-scenes aspects that make your website easier for search engines to crawl and index. It includes:

• Website speed and performance.
• Mobile friendliness.
• Secure connections (HTTPS).
• Proper use of structured data (schema).
• Fixing broken links or errors.
• Without strong technical SEO, even the best content can struggle to rank well.
• …more

SERPs

SERP stands for “Search Engine Results Page”. This is the page you see after typing a search into Google.

SERPs are no longer just a list of blue links. You may also see featured snippets, knowledge panels, image carousels, maps and videos. Understanding how your content can appear in different parts of the SERP is an important part of SEO.

Organic vs paid results

When you search for something on Google, you will usually see two types of results:

• Organic results: unpaid listings that appear because of SEO efforts.
• Paid results: advertisements that businesses pay to display. Look for “Sponsored” to identify a paid result.

SEO focuses on the organic side. Paid advertising is known as search engine marketing (SEM). Both have their place, but SEO is valuable because it continues to bring traffic long after you have done the work.

Ranking factors

Search engines use hundreds of signals to decide where a website should appear in the results. These are called ranking factors. They include relevance of the content, quality of backlinks, page speed, mobile usability, and many more.

While no one knows the exact algorithm, focusing on creating high-quality, useful content and providing a good user experience covers many of the most important factors.

Crawling and indexing

Search engines use automated bots called crawlers or spiders to browse the web. These bots discover new content and record it in a search engine’s database, which is known as the index.

If your website is not crawled and indexed properly, it will not show up in search results. Submitting a sitemap to Google Search Console can help ensure your pages are discovered.

Sitemaps

A Sitemap is a file that lists all the important pages on your website, helping search engines like Google understand the structure of your site. It acts as a map that guides search engine crawlers through your content so nothing important is missed. While search engines can usually find pages on their own, a Sitemap ensures that your most valuable content is discovered and indexed quickly.

A Sitemap can be created in different formats, but the most common is XML. This format is designed specifically for search engines rather than people. For instance, your XML Sitemap might include your main service pages, blog posts, and product categories. There are also HTML Sitemaps, which are made for human visitors to help them navigate through the site more easily.

Tip, you can often access any website’s sitemap by putting /sitemap.xml or /sitemap_index.xml after their homepage URL.. That’s because all sitemaps need to be publicly accessible for crawlers to find them!

For SEO, a Sitemap is useful because it signals to search engines which pages matter most and how they connect to each other. This can be especially important if your site is new, very large, or has pages that are not well linked internally. Without a Sitemap, some pages might never get discovered by search engine crawlers, which could hurt your visibility in search results.

Having a Sitemap does not guarantee high rankings, but it improves the chances of your content being indexed properly. The better your site is indexed, the more opportunity you have to rank for the keywords you are targeting.

In simple terms, a Sitemap is a way to give search engines a clear guide to your site. It makes sure they can see the bigger picture of your content and not overlook key pages.

User experience (UX) and SEO

Google increasingly rewards websites that are easy to use. Good SEO and good user experience go hand in hand. Things like clear navigation, fast loading times, mobile-friendly layouts, and easy-to-read content all matter for both visitors and search engines.

User experience refers to how people interact with your site. If your site is difficult to navigate, takes too long to load, or looks cluttered, users are likely to leave quickly. Search engines notice this behaviour, and high bounce rates or low engagement can signal that a page is not providing what visitors are looking for. Over time, this can negatively affect your rankings.

On the other hand, when a website is designed with the user in mind, people stay longer, view more pages, and are more likely to convert. Features such as a simple menu structure, clear calls to action, and content that is broken into short, readable sections all contribute to a smoother experience. These improvements are not just for human visitors either. Search engines crawl sites more effectively when the layout and internal links are organised.

Mobile experience is another key factor. With the majority of searches now taking place on mobile devices, Google uses a mobile-first approach when indexing websites. This means that if your site does not display well on smaller screens, it could harm your SEO performance. Responsive design, larger tap targets, and easy-to-read fonts are no longer optional, they are essential.

Site speed also plays a major role. Pages that take too long to load frustrate users and can lead them to abandon your site altogether. Google considers page speed a ranking factor, so optimising images, reducing unnecessary code, and using reliable hosting can all have a positive impact.

Ultimately, UX is the human side of SEO. Search engines are designed to deliver the best possible results to users, so the easier and more enjoyable your website is to use, the more likely it is to be rewarded in search results. In other words, when you design for people first, you often end up satisfying search engines too.

Why SEO matters

For businesses of all sizes, SEO can:

• Drive targeted traffic without ongoing ad spend.
• Build trust and credibility with potential customers.
• Improve brand awareness by appearing at the top of search results.
• Deliver long-term results once your website is established.
• While SEO takes time and effort, it can be one of the most cost-effective ways to grow your presence online.

Why it’s important to know the terminology

Learning the terminology of SEO is the first step to understanding how it works. Once you are comfortable with these concepts, you will be able to dive deeper into strategies, tools and analytics.

If you want to go further, you might like to read our guide on free and paid SEO tools worth using, which explains how different tools can help you with keyword research, content optimisation, and tracking your progress.

SEO Glossary