SEO, short for search engine optimisation, is the work on your website that lets search engines such as Google find, understand and show your pages when someone searches for what you offer. SEO covers technical work so that pages can be reached, content that answers customer questions, and links from other websites that show your pages are worth visiting.
How does a search engine work?
In its guide to how Search works, Google describes three stages. A page can drop out at each one.
- Crawling. A Google program called Googlebot fetches pages and downloads their content. According to the SEO Starter Guide, Google finds new pages mostly through links from pages it already knows. Googlebot skips pages that are excluded in robots.txt or that require a login. Google also runs JavaScript along the way.
- Indexing. Google analyses the text, images and key tags on a page and stores that information in its index. When pages are very similar, Google groups them and picks one to represent the group: the canonical page. Not every fetched page makes it into the index.
- Serving results. When someone searches, Google looks in the index for the most relevant and useful pages. Google says hundreds of factors play a part, including the searcher’s language, location and device.
Google adds that it does not accept payment to crawl a site more often or rank it higher, and that crawling, indexing or showing a page is never guaranteed. Not even when you follow every guideline.
What work does SEO involve?
The work falls roughly into three kinds, and they depend on each other. The best text does nothing if Google cannot fetch the page, and a technically flawless page without useful content attracts few searchers.
| Kind of work | What it is about | Examples |
|---|---|---|
| Technical | Can Google fetch your pages, read them and add them to its index? | Status codes, robots.txt, noindex, canonicals, sitemap, load time, mobile display |
| Content | Does the page answer the question someone is searching with? | Service and category pages, explanations, comparisons, titles and descriptions |
| Authority | Do other websites link to your pages? | Mentions by trade associations, suppliers, local media and partners |
Technical: can Google reach your pages?
Technical SEO asks whether a search engine can fetch and understand your pages without obstacles. Many problems are invisible to visitors. A page can look fine in your browser while an instruction in the code asks Google not to include it.
The main parts:
- Status codes. A page you want people to find returns a 200 response. Pages you remove send visitors on to the best replacement with a 301 redirect.
- Robots.txt and noindex. Robots.txt tells a crawler which addresses it may fetch. Noindex asks a search engine not to include a page in its index. They are two different instructions and are often confused. More under robots.txt and noindex.
- Canonicals. A canonical URL tells search engines which version of a page is the main one when the same content appears at more than one address.
- Internal links. Google follows links to discover new pages. A page that no link points to is hard to find.
- Speed and mobile. Google uses the mobile version of your site for indexing. Core Web Vitals measure loading, responsiveness and visual stability. Google’s explanation of page experience is clear that relevance comes first: a fast page with a weak answer does not beat a slower page with the best answer.
Robots.txt or noindex?
| robots.txt | noindex | |
|---|---|---|
| Which question does it answer? | May this crawler fetch this address? | May this page go into the index? |
| Where does it live? | In one file in the root of your domain | In the HTML of the page itself, or in an HTTP header |
| What do you use it for? | Areas crawlers do not need to fetch, such as your own site search results | Pages visitors may see but that do not belong in Google, such as an order confirmation page |
Every check is set out in the technical SEO checklist.
Content: does your page answer the question?
A search engine shows pages that answer a search well. Google’s guidance on helpful, reliable content asks you to write for people, with first-hand knowledge. It suggests questions such as: would someone who came straight to your site find this page useful, and do they know enough after reading it to take the next step?
In practice that means:
- Each page gets one clear job. A category page helps people choose between products. A service page explains what you do, for whom and what it delivers. An explainer answers one question.
- You write from what customers ask. The questions your customer service or sales team hear are often exactly the searches you want to be found for. The step-by-step guide to customer questions and keywords shows how to collect them.
- Title and description match the content. The title tag and meta description help decide what someone sees in the search results. Google may change the title it shows, for example when it is outdated or does not fit the page, as its documentation on title links explains.
This is how it looks to someone searching:
buy e-bike york
- bikecompare.example.com › e-bikesCompare and buy e-bikesModels from shops across the country.
- thespoke.example.com › e-bikesBuy an e-bike in York with a test rideSee our e-bikes in the shop on Example Street and book a test ride.
- cyclingblog.example.com › buyingWhat does a good e-bike cost?What to look for in battery, motor and frame.
A title that says what is on the page helps the searcher choose. Compare:
A title tag that says what is on the page
VoorHome
NaBuy an e-bike in York with a test ride | The Spoke Cycle Shop
Authority: why do links from other sites count?
Links from other websites help in two ways. Google uses them to find new pages, and a link suggests that someone else thinks your page is worth visiting. The SEO Starter Guide says PageRank, the system that takes links into account, is one of many signals.
A mention by your trade association, a supplier or a local newspaper says more than a long list of links from sites nobody visits. If you buy a link or get one in return for something, Google asks you to mark it with rel="sponsored", according to its link best practices.
What matters less than people often think?
The SEO Starter Guide lists several things Google says you need not spend time on:
| Common advice | What Google says |
|---|---|
| Fill in the meta keywords tag | Google Search does not use that tag. |
| Write at least a certain number of words | The length of content alone does not matter for ranking. |
| Put your keyword in your domain name | It has hardly any effect on ranking. |
| Headings must follow a strict order | The order does not matter for Google Search. A logical order still helps visitors and accessibility. |
| Duplicate content gets you penalised | Duplicate content on your own site does not break the spam policies, although it is inefficient. |
How do SEO and AI answers relate?
Above some search results, Google shows an AI-generated summary: AI Overviews. In its documentation on AI features, Google writes that the usual SEO best practices remain relevant there and that no extra requirements or special files are needed.
Other AI assistants, such as ChatGPT and Perplexity, fall outside that Google documentation and have their own rules. The work on visibility in their answers is called GEO. A sound technical foundation and clear content help with both. The differences are set out in SEO, GEO and AEO: what is the difference?
How does Outseen approach SEO?
Outseen starts with your customers’ questions and the pages that should answer them. For the technical research we use Atlas, developed by Outseen: our own research engine for SEO and GEO. Atlas examines the public code your website returns, such as titles, headings, indexing instructions, canonicals and internal links, and records for every finding what it observed, on which URL and when. A specialist assesses what that means for your website and which work comes first. More on the approach is on the SEO page.
What does this mean for your business?
SEO starts with whether Google can find your most important pages, and whether those pages answer your customers’ questions. You do not need to be a specialist for that. You can take these steps yourself:
- Add your website to Google Search Console. It shows which pages Google has indexed, which searches you appear for and which errors Google runs into.
- Check whether your site is in Google. Search for
site:yourdomain.com. If results from your site appear, at least part of it is in the index. - Go through your most important pages. Does each page have its own title that says what is on it? Does the text answer the question a customer has?
- Link logically between your pages. From an explainer, link to the service or category it belongs to, with link text that says where the link goes.
- Give it time. Google says some changes take effect within a few hours and others only after months. The details are in how long does SEO take to show results?