Plain definitions of the search, website and marketing terms buyers meet. Below: why each matters, the Core Web Vitals thresholds, our view and every source.
Facts checked against each publisher's own documentation on 7 October 2026. Sources are listed at the end.
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Every term, A to ZTopic 1 of 7
The core ideas behind being found in search, and how buyers phrase what they need.
SEO servicesShowing this topic only. Show all topics
Search engine optimisation (SEO) is the work of helping search engines understand your content and helping people find your site through search. It covers what you publish, how the site is built and how other sites refer to it.
Why it matters. Organic search brings visits you do not pay for per click, and Google says optimising for its generative AI features is still SEO.
Sources: Google: SEO Starter Guide, Google: Guide to optimising for generative AI search
Search intent is the need behind a query: to learn something, compare options, find a particular site or act now. Two searches with similar words can carry different intents.
Why it matters. A page that serves the wrong intent leaves the searcher unsatisfied, so intent should decide which page owns each query.
Keyword research is finding the words and questions your buyers type into search engines, then judging each one by intent, relevance and the effort needed to compete. The result is a set of topics to cover, not a page for every phrase.
Why it matters. It points your content at the questions buyers actually ask, rather than at the language used inside your business.
Topic 2 of 7
How Google's AI features and other answer engines use pages, and what each acronym means.
AI search servicesShowing this topic only. Show all topics
Answer engine optimisation (AEO) is the practice of structuring a page so a search engine or assistant can find a direct, accurate answer to a specific question and show it, quote it or read it aloud.
Why it matters. Answer boxes and assistants show short answers, so a page that states its answer plainly at the start of each section gives them something accurate to use.
Generative engine optimisation (GEO) is the work of making your business easy for AI answer engines to understand and cite accurately, through clear source content and facts that stay consistent wherever they appear.
Why it matters. The term comes from a 2023 research paper, and Google's own guide treats optimising for generative AI search as SEO, so GEO builds on SEO rather than replacing it.
Sources: arXiv: GEO: Generative Engine Optimization, Aggarwal and others, November 2023, Google: Guide to optimising for generative AI search
AIO is used in two ways: for AI optimisation in general, and for optimising pages for Google's AI Overviews. There is no agreed definition, so ask a provider which one they mean.
Why it matters. AIO, AEO and GEO describe overlapping work, so compare providers on the deliverables they list rather than the acronym they use.
AI Overviews are AI-generated summaries in Google Search results that give the gist of a topic or question, with links to explore further. Google shows one only when its systems judge that it adds to the usual results, so many searches show none.
Why it matters. To be eligible as a supporting link, a page must be indexed and able to show a snippet in Google Search. There is no special markup or file to add.
AI Mode is a Google Search experience for questions that need further exploration, reasoning or complex comparisons, where people can ask follow-up questions. Like AI Overviews, it links to relevant pages.
Why it matters. Search Console counts each follow-up question as a new query, and a click from AI Mode to an external page counts as a click.
Sources: Google: AI features and your website, Search Console Help: How impressions, position and clicks are counted
Query fan-out is a technique Google says AI Overviews and AI Mode may use: running several related searches across subtopics and data sources to build one response.
Why it matters. One answer can draw on several related searches, which is a reason to answer the follow-up questions around a topic as well as the main one.
llms.txt is a proposed Markdown file at the root of a website that gives AI tools a short guide to its content. Jeremy Howard proposed it in September 2024.
Why it matters. Google says the file is not needed for Google Search and will not help or harm visibility there, though other services may use it.
Sources: llmstxt.org: The /llms.txt file, a proposal by Jeremy Howard, Google: Documentation updates, including the 15 June 2026 note on llms.txt
Topic 3 of 7
How search engines find, read and store your pages, and the files that steer them.
Website OptimiserShowing this topic only. Show all topics
Crawling is how search engines discover pages: automated programs called crawlers download the text, images and video on the pages they find. Google's crawler is called Googlebot.
Why it matters. Crawlers find new pages by following links and reading sitemaps, so a page that nothing links to may never be found.
Sources: Google: In-depth guide to how Google Search works, Google: Link best practices for Google
Indexing is the stage where a search engine analyses a page's text, images and video and stores what it learns in its index, a very large database. Only indexed pages can appear in its results.
Why it matters. Google does not guarantee it will index a page, and a page must be indexed to appear as a link in AI Overviews or AI Mode.
Sources: Google: In-depth guide to how Google Search works, Google: AI features and your website
Crawl budget is the set of URLs on a site that Google can and wants to crawl. It combines how much crawling the server can handle with how much Google wants to crawl.
Why it matters. Google's guide is written for large sites, such as those with over a million pages changing weekly. If your new pages are crawled the day they are published, Google says you do not need its guide.
robots.txt is a file at the root of a site that tells search engine crawlers which URLs they may access. It is mainly used to avoid overloading a site with requests.
Why it matters. It does not keep a page out of Google, and a blocked page can still be indexed if other sites link to it. Use noindex or a password for that.
Sources: Google: Introduction to robots.txt, Google: How to write and submit a robots.txt file, Google: Block Search indexing with noindex
An XML sitemap is a file that tells search engines about the pages, videos and other files on a site, and how they relate.
Why it matters. It helps search engines discover URLs but does not guarantee they are crawled or indexed. Google says a well-linked site of about 500 pages or fewer may not need one.
Source: Google: Learn about sitemaps
A canonical URL is the address Google chooses to represent a set of duplicate or very similar pages. A site can state its preference with rel="canonical", which Google treats as a hint, not a rule.
Why it matters. Google usually shows the canonical page in results and crawls it most often, so make the version you want found the clear choice.
A 301 redirect is a server response that tells browsers and search engines a page has moved permanently to a new address. Google follows it and uses it as a signal that the new address should be the canonical one.
Why it matters. When URLs change in a redesign or migration, Google recommends permanent server-side redirects wherever possible, so visitors and search engines reach the right page.
Structured data is code, such as JSON-LD, that describes a page's content in a standard format, such as who published it or what it offers, so search engines can classify it.
Why it matters. It can make a page eligible for rich results, with no guarantee, and Google says it is not required for its generative AI features. Mark up only what readers can see.
Sources: Google: Introduction to structured data markup, Google: General structured data guidelines, Google: Guide to optimising for generative AI search
IndexNow is a way for a website to tell participating search engines straight away when a URL is added, updated or deleted. A submission to one engine is shared with the others.
Why it matters. Bing, Naver, Seznam.cz, Yandex and Yep take part, Google does not, and a submission does not guarantee indexing.
Sources: IndexNow: IndexNow and its participating search engines, IndexNow: IndexNow frequently asked questions
Topic 4 of 7
What Google rewards, what it treats as spam and how its updates move rankings.
Our editorial standardShowing this topic only. Show all topics
E-E-A-T stands for experience, expertise, authoritativeness and trustworthiness, the aspects of content Google's systems look for when they prioritise helpful results. Google says trust is the most important of the four.
Why it matters. Google says E-E-A-T is not a ranking factor in itself, so it is shown through real authors, sources and first-hand detail, not claimed with a badge.
Source: Google: Creating helpful, reliable, people-first content
Scaled content abuse is Google's spam policy against generating many pages mainly to manipulate rankings rather than to help people, however the pages are made.
Why it matters. Google's first example is using generative AI to produce many pages without adding value, so the risk is volume without value, not the tool.
Sources: Google: Spam policies for Google web search, Google: Guidance on using generative AI content
Keyword stuffing is filling a page with keywords or numbers in an attempt to manipulate rankings. It is one of the practices Google's spam policies name.
Why it matters. Repetition reads badly and puts the page at risk, so write for the reader and use the words buyers use where they fit naturally.
Sources: Google: Spam policies for Google web search, Google: SEO Starter Guide
A core update is a significant, broad change to Google's ranking systems, made several times a year and announced on the Google Search Status Dashboard. Core updates do not target specific sites or pages.
Why it matters. A drop after a core update does not mean a site broke a policy. Google suggests waiting a full week after the rollout ends before analysing the change.
Sources: Google: Google Search's core updates, Google Search Status Dashboard: Ranking updates, including the March and May 2026 core updates and the September 2026 spam update
A spam update is a notable improvement to Google's automated spam detection, which includes its AI-based system SpamBrain. The September 2026 spam update began on 24 September 2026.
Why it matters. Sites that break the spam policies may rank lower or drop out of results, and Google says recovery can take months after the fixes.
Sources: Google: Google Search spam updates, Google Search Status Dashboard: Ranking updates, including the March and May 2026 core updates and the September 2026 spam update
Programmatic SEO is publishing many pages from a template and a dataset, such as one page for each location, product or integration.
Why it matters. Each page needs its own data or help. Many near-identical pages made mainly to rank are what Google's scaled content abuse policy describes.
Topic 5 of 7
How links between sites and pages carry trust, and the scores tools use to estimate it.
Link building servicesShowing this topic only. Show all topics
A backlink is a link from another website to yours. Google uses links as a signal when judging how relevant pages are and to find new pages to crawl.
Why it matters. Relevant links help search engines find and assess your pages. Buying them, or swapping them in bulk, breaks Google's link spam policy.
Sources: Google: Link best practices for Google, Google: Spam policies for Google web search
White-hat link building is earning links from relevant, independent websites by giving each one a genuine reason to link, such as a useful page, original data, expert commentary or a fix for a broken link or an unlinked mention.
Why it matters. When Google neutralises spammy links, any ranking benefit they gave is lost. Earned links do not carry that risk.
Link spam is creating links to or from a site mainly to manipulate search rankings, such as buying or selling links for ranking or exchanging links excessively.
Why it matters. Paid placements are allowed when the link is marked rel="sponsored", Google's label for adverts and paid links.
Sources: Google: Spam policies for Google web search, Google: Qualify your outbound links to Google
Domain Rating (DR) is an Ahrefs score from 0 to 100 that shows the strength of a website's backlink profile compared with the other sites in Ahrefs' database.
Why it matters. It is Ahrefs' own estimate, not a Google metric, so treat it as a scorecard for link building rather than the goal.
Internal linking is linking from one page on your site to another, using descriptive anchor text that says what the destination is about.
Why it matters. Google uses links to find and understand pages, and says every page you care about should have a link from at least one other page on your site.
Topic 6 of 7
How fast and stable a page feels to real visitors, and the pages that turn visits into enquiries.
Web development servicesShowing this topic only. Show all topics
Core Web Vitals are three Google metrics for real-world page experience: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability.
Why it matters. Google says good page experience aligns with what its core ranking systems seek to reward. Scores are read at the 75th percentile of real visits, so one lab test is a diagnosis, not the result.
Sources: Google: Core Web Vitals and Google Search results, web.dev: Web Vitals, web.dev: Why lab and field data can be different
Largest Contentful Paint (LCP) measures loading: the time until the largest image, text block or video in view has rendered, counted from when the visitor first navigated to the page.
Why it matters. Until the main content appears, a visitor has nothing to read. Good is 2.5 seconds or less, and more than 4 seconds is poor.
Interaction to Next Paint (INP) measures responsiveness: how quickly a page reacts to clicks, taps and key presses, reported as a value that all or nearly all interactions fall within. It replaced First Input Delay as a Core Web Vital.
Why it matters. A button or menu that lags makes a page feel broken. Good is 200 milliseconds or less, and more than 500 milliseconds is poor.
Cumulative Layout Shift (CLS) measures visual stability: how much content moves unexpectedly while a page is open, scored on the largest burst of layout shifts.
Why it matters. Content that jumps can make a visitor tap the wrong thing. Good is 0.1 or less, and more than 0.25 is poor.
A landing page is the page a visitor arrives on from an advert, email or search result, usually built around one offer and one next step.
Why it matters. On paid traffic, it is where a click you paid for becomes an enquiry or is lost, so its speed and clarity on a phone matter.
| Metric | Measures | Good | Poor |
|---|---|---|---|
| LCP | Loading | 2.5 s or less | Over 4 s |
| INP | Responsiveness | 200 ms or less | Over 500 ms |
| CLS | Visual stability | 0.1 or less | Over 0.25 |
Read at the 75th percentile of page loads, for mobile and desktop separately. Anything between good and poor needs improvement. Times are in seconds (s) and milliseconds (ms).
Sources: web.dev: Web Vitals, web.dev: Largest Contentful Paint (LCP), web.dev: Interaction to Next Paint (INP), web.dev: Cumulative Layout Shift (CLS)
Topic 7 of 7
The reports and ratios that show whether search work is turning into enquiries.
Inbound lead generationShowing this topic only. Show all topics
Google Search Console is Google's tool for site owners to see how their site performs in Google Search, which searches show their pages and what crawling or indexing problems need fixing.
Why it matters. It is Google's own record of clicks and impressions. Since 31 August 2026 its Generative AI performance report, with impressions from AI Overviews and AI Mode, is available to all websites.
Sources: Google: Get started with Search Console, Search Console Help: Performance report for Search results, Search Console Help: Generative AI performance report
Click-through rate (CTR) is clicks divided by impressions: the share of people who saw your result and clicked it. 30 clicks from 1,000 impressions is a 3% CTR.
Why it matters. Many impressions with few clicks can mean the search is answered on the results page or the title does not match the need, so check which before rewriting.
Source: Search Console Help: Performance report for Search results
Average position is the mean ranking of the topmost result from your site, as reported in Search Console. An AI Overview takes one position, and every link inside it is given that position.
Why it matters. Because links in an AI Overview share its position, average position alone can mislead. Read it beside clicks and enquiries.
Sources: Search Console Help: Performance report for Search results, Search Console Help: How impressions, position and clicks are counted
Conversion rate is the share of visits that end in the action you want, such as an enquiry or a booked call. 20 enquiries from 1,000 visits is a 2% conversion rate.
Why it matters. It shows whether traffic is turning into business. Compare it by device and traffic source, because an average can hide a weak mobile page.
Lead generation is attracting potential customers and turning their interest into an enquiry your sales team can follow up. Inbound lead generation does it through search, content and the website rather than cold outreach.
Why it matters. Enquiries are the measure that SEO, content and website work should answer to, ahead of rankings or traffic.
Our view, labelled as opinion
This is our opinion, from doing the work. Each point links to the term it is about.
How we work with clientsWe would not buy AEO, GEO and SEO as three separate retainers. The clear pages, real evidence and open crawl access that serve one serve all three.
AIO, definedA rising DR can follow good link building. A DR target invites the bought links that Google's spam policies prohibit.
Domain Rating (DR), definedEvery link in an AI Overview shares one position, so the number cannot tell you whether anyone visited. Clicks and enquiries can.
Average position, definedCore Web Vitals describe real visitors on real devices. A lab test on one machine is a good diagnosis, but real-visitor data is what counts.
Core Web Vitals, definedIndex
All 40 terms in one list, each with its topic. Select a term to read its definition.
Back to the topicsSources
Checked on 7 October 2026 against each publisher's own pages. Recheck a source before relying on a detail.
Our editorial standardTell us which of these matters most to your business. We agree the scope before any work starts.
