# How does SEO work? A plain-English explanation - Link: https://peacocksearch.com/how-does-seo-work/ - Published: 2026-10-22T08:00:00+00:00 - Author: Peacock Search SEO works by helping search engines find and understand your pages, so they can show them to people searching for what you offer. Google Search runs in three stages: it crawls the web to discover pages, indexes what it finds and serves results when someone searches. SEO is the work of getting your important pages through each stage and giving Google good reason to show them ahead of the alternatives. Plenty of owners are sold SEO without anyone explaining it. So how does SEO work at each stage, and what should a supplier be doing there? We’ve answered both from Google’s own documentation. ## What is SEO? SEO stands for search engine optimisation. Google’s [SEO Starter Guide](https://developers.google.com/search/docs/fundamentals/seo-starter-guide) describes it as helping search engines understand your content, and helping people find your site and decide whether to visit it from a search engine. It deals with the unpaid results, not the ads. You’ll also hear “an SEO” used for the person or firm doing the work, as in the title of Google’s guide to hiring one, [“Do you need an SEO?”](https://developers.google.com/search/docs/fundamentals/do-i-need-seo) ## How Google Search works in three stages Google’s [in-depth guide to how Search works](https://developers.google.com/search/docs/fundamentals/how-search-works) splits it into crawling, indexing and serving search results, and notes that not all pages make it through each stage. Keep two of its points in mind when you read an SEO proposal. Google doesn’t accept payment to crawl a site more often or to rank it higher. And it doesn’t guarantee that it will crawl, index or serve any page, even one that follows Google’s own guidelines, the Search Essentials. ### Crawling There’s no central list of every page on the web, so Google keeps looking for new and updated ones. Its starter guide says the vast majority of the new pages Google finds every day come through links. Google also reads sitemaps, which are files listing the pages you want found. A program called Googlebot then fetches the pages it chooses to crawl (not every page Google finds) and renders them, much as your browser does. Common reasons Googlebot can’t reach a page, Google says, are server problems, network issues and rules in the site’s robots.txt file that block it. This is where [technical SEO](https://peacocksearch.com/services/technical-seo/) starts. A supplier should be able to tell you whether Google can reach your important pages and, if it can’t, why not. ### Indexing Next, Google tries to understand what each page is about, from its text, images and video. What it learns can then be stored in the Google index, a large database. Google names three common reasons pages are left out of it: low-quality content, a tag in the page’s code telling Google not to index it, and a site design that makes indexing difficult. Search Console, Google’s tool for site owners, shows which of your pages are indexed and why others aren’t. Any supplier should look there before recommending anything else. ### Serving results When someone searches, Google looks through its index for matching pages and returns the ones it believes are the highest quality and most relevant. Relevance is decided by hundreds of factors, which can include the searcher’s location, language and device. A page can be indexed and still not appear, for example because it isn’t relevant to the search, its quality is low or a tag in the page’s code stops it being shown. ## What decides where a page ranks Google’s [explanation of how it ranks results](https://www.google.com/search/howsearchworks/how-search-works/ranking-results/) lists its key signals. They include the meaning of the search, the relevance of the content, its quality, its usability and the context of the search, such as where you are and your settings. The weight given to each varies from one search to another. Google’s ranking systems are designed to prioritise helpful, reliable information created to benefit people, rather than content made to manipulate rankings, according to its [guidance on helpful content](https://developers.google.com/search/docs/fundamentals/creating-helpful-content). Google’s explanation of ranking also names one quality signal: whether other prominent websites link to or refer to the content. Usability counts too. When other signals are roughly equal, pages people find easier to use, such as mobile-friendly pages that load quickly, may do better. Some things don’t count, whatever a proposal claims. Google’s starter guide says it doesn’t use the keywords meta tag, that content length alone doesn’t matter for ranking and that E-E-A-T (experience, expertise, authoritativeness and trustworthiness) isn’t a ranking factor in itself. Keyword stuffing is against its spam policies. ## How does SEO work in practice? Each stage points to a kind of work, and a proposal should say which kinds your site needs and in what order. Google’s hiring guide says that if you run a small local business, you can probably do much of the work yourself. The same work applies to Google’s AI Overviews and AI Mode: its [guide to AI features](https://developers.google.com/search/docs/appearance/ai-features) says the usual SEO best practices apply, with no extra requirements. ### Technical fixes Google’s [technical requirements](https://developers.google.com/search/docs/essentials/technical) are short. To be eligible for indexing, a page must be accessible to Googlebot, must work (it has to return an HTTP 200, or “success”, code) and must have content Google can index. Technical SEO checks those for every page that matters, then deals with speed, mobile use, duplicate pages and anything that hides content from Google. ### Content Google’s starter guide says that creating content people find compelling and useful will likely influence your presence in search more than anything else it suggests. Think about the words people might search for. For a service business, that usually means a clear page for each main service, naming the places you work and written in the words your customers use. ### Links and mentions Links help Google find pages, and links from prominent sites are one of the signals it uses to judge quality. The useful ones are earned, such as a local paper covering your work. Buying or selling links for ranking purposes is [link spam under Google’s policies](https://developers.google.com/search/docs/essentials/spam-policies), and Google’s hiring guide adds that you should never have to link to an SEO from your site. ### Local search For searches with local intent, Google shows nearby businesses on Maps and in Search. These results depend mainly on how relevant a business is to the search, how far it is from the searcher and how well known it is, according to Google’s [advice on local ranking](https://support.google.com/business/answer/7091?hl=en-GB). There’s no way to request or pay for a better local ranking. [Local SEO](https://peacocksearch.com/services/local-seo/) works on what you can influence: a complete and accurate Google Business Profile, reviews, and the links and mentions that make a business better known. ## Organic results and ads are separate “Organic SEO” means the same as SEO: work on Google’s non-advertising results, which the hiring guide notes are often called organic search. Google only sells ad space, so [no one can buy better placement in organic results](https://www.google.com/search/howsearchworks/our-approach/ads-on-search/). Its ads are always labelled “Sponsored” or “Ad” and shown apart from the search results. Advertising with Google has no effect on your site’s presence in its search results, the hiring guide confirms, and it costs nothing to appear in organic results. ## What SEO can’t do No one can guarantee a #1 ranking on Google, according to Google’s hiring guide, which warns against anyone who claims a “special relationship” with Google or advertises a “priority submit”. And not every change makes a noticeable difference, the starter guide adds. Nor can technical work make a weak page deserve a ranking. If a page doesn’t answer the search better than the pages already there, the page itself has to improve. Honesty about this is a fair first test when [choosing an SEO agency or consultant](https://peacocksearch.com/seo-agency-or-consultant/). Do they explain what they’ll change and why, or promise outcomes Google says nobody can promise? ## How long before anything changes Some changes might take effect in a few hours and others could take several months, according to Google’s starter guide. It suggests allowing a few weeks before you assess the effect. Fixes that unblock pages often show first, because Google sees the fix as soon as it crawls those pages again. Rankings for competitive searches take longer. We’ve written more on [how long SEO takes to work](https://peacocksearch.com/how-long-does-seo-take/). ## Where to start with your own site 1. **Check Google can see you.** Search Google for _site:_ followed by your domain. If you see results pointing to your site, you’re in Google’s index. 2. **Set up Search Console.** It shows how Google crawls, indexes and serves your site, as Google’s [Search Console guide](https://developers.google.com/search/docs/monitor-debug/search-console-start) explains. Keep the account in your own name. 3. **Check your Google Business Profile.** If you serve customers locally, Google says complete and accurate details make a business more likely to show in local results. 4. **Read any proposal against Google’s guidance.** The hiring guide suggests asking whether a supplier follows the Search Essentials and cites official Google documentation, and giving only read access to Search Console for an audit. 5. **Decide what you want to win.** An SEO strategy is the written plan that sets which searches matter most to your business, the order to go after them and what each one needs. Our [search strategy](https://peacocksearch.com/services/search-strategy/) work begins with this step. If you’d rather someone did the work, our [SEO services](https://peacocksearch.com/services/seo/) start from a written plan you approve before anything changes, with every account kept in your name. To see where your own site stands on Google, Maps and AI answers, [ask for a free visibility audit](https://peacocksearch.com/contact/#audit). It names the three things to fix first. ## Questions ### Is SEO free? Appearing in Google’s organic results costs nothing, and Google doesn’t accept payment to rank sites. What costs money is the time it takes to fix, write and promote pages. ### What is an SEO? An SEO is the person or firm who does search engine optimisation. Google’s own guide to hiring one says a small local business can probably do much of the work itself. ### Can anyone guarantee a first-page ranking? No. Google says no one can guarantee a #1 ranking, and it doesn’t guarantee it will crawl, index or show any page, so treat a ranking guarantee as a warning sign. ### Do Google Ads help my SEO? No. Google says advertising with it has no effect on your site’s presence in its search results. ### Does SEO work for Google’s AI Overviews? The same work applies: Google says the usual SEO best practices hold for AI Overviews and AI Mode, with no extra requirements. To appear as a supporting link, a page has to be indexed and eligible to show in Search with a snippet.