SEO Glossary: 130+ SEO Terms and Definitions in Plain English (Including AEO and GEO)
Plain-English SEO terminology and vocabulary: 130+ SEO terms, definitions and acronyms, from crawling and canonicals to AI Overviews, AEO and GEO.
SEO comes with a lot of vocabulary. These are the terms you’re most likely to hear from an agency, a developer, a report or an SEO tool, each explained in a sentence or two of plain English. I’ve included the newer AI search terms, a list of acronyms, and the pairs of terms people mix up most often.
The 20 SEO terms to know first
If you’re new to SEO, learn these first. Everything else builds on them.
- Search engine optimization (SEO)
- Search intent
- Keyword
- SERP (search engine results page)
- Organic results
- Crawling
- Indexing
- Title tag
- Meta description
- Headings (H1, H2, H3)
- Internal link
- Backlink
- E-E-A-T
- Core Web Vitals
- Structured data (schema markup)
- Google Business Profile
- Google Search Console
- Click-through rate (CTR)
- AI Overview
- Answer engine optimization (AEO)
Search basics
Search engine optimization (SEO)
Improving a website so it appears more often, and higher, in the unpaid results of search engines like Google and Bing, and increasingly in AI answers.
Search engine
Software that finds, organizes and ranks web content in response to a search, such as Google, Bing or DuckDuckGo.
Search query
The exact words someone types or speaks into a search engine. A keyword is what you target; a query is what people actually type.
SERP (search engine results page)
The page you see after searching. It can include ads, organic results, a map, images, videos and AI-generated answers.
Organic results
The unpaid listings in search results, earned through relevance and quality rather than bought.
Paid results
Listings that advertisers pay for, labelled “Sponsored”. They sit above and below the organic results.
Search engine marketing (SEM)
Marketing in search engines, most often used to mean paid search ads such as Google Ads. SEO and SEM are not interchangeable: SEO earns unpaid rankings, while SEM usually means paying for clicks.
SERP features
Anything on the results page beyond a standard blue link, such as featured snippets, People Also Ask, maps, images, videos and AI Overviews.
Featured snippet
A highlighted answer quoted from a web page at the top of the results.
People Also Ask (PAA)
An expandable box of related questions, each answered with a snippet from a web page.
Knowledge panel
The box of facts about a business, person or thing, usually on the right of the results on desktop, drawn from Google’s Knowledge Graph.
Rich results
Search listings with extra details, such as review stars, prices, recipe times or event dates. Most are powered by structured data.
Zero-click search
A search answered on the results page itself, so the searcher never clicks through to a website.
Ranking
Where a page appears in the results for a particular search. Rankings change by location, device and person, so treat any single ranking as a snapshot.
Algorithm
The systems a search engine uses to decide which pages to show for a search, and in what order.
Ranking factor
Something a search engine weighs when ranking pages, such as relevance to the search, links from other sites or page experience. Also called a ranking signal.
Keywords and search intent
Keyword
A word or phrase people type or say into a search engine, and that you want your page to appear for.
Keyword research
Finding the words and questions your customers search for, and judging which are worth targeting based on intent, volume and competition.
Search volume
The estimated number of times a keyword is searched each month. It comes from tools and is always an estimate, not an exact count.
Keyword difficulty
A tool’s estimate of how hard it is to reach the first page for a keyword, usually based on the strength of the pages already ranking. Every tool calculates it differently.
Head term
A short, broad, high-volume search like “SEO” or “plumber”. Also called a short-tail keyword. Head terms are competitive and their intent is often unclear.
Long-tail keyword
A longer, more specific search, like “emergency furnace repair Cochrane”. Long-tail searches have less volume but clearer intent and less competition.
Search intent
What the searcher actually wants. Intent is usually informational (learn something), navigational (find a specific site), commercial (compare options) or transactional (buy or book).
Branded keyword
A search that includes your business or product name. Non-branded searches, without your name, show how well you reach people who don’t know you yet.
Keyword mapping
Assigning each target keyword to one page on your site, so every page has a clear job and pages don’t compete with each other.
Keyword cannibalization
When several of your pages compete for the same search, often weakening all of them.
Keyword stuffing
Repeating keywords unnaturally to try to manipulate rankings. It breaks Google’s spam policies and reads badly.
Topic cluster
A group of pages covering related subtopics, all linked to a central pillar page, that together cover a subject in depth.
Pillar page
A broad page on a core topic that links out to more detailed pages in its topic cluster.
Ranch-style SEO
A content strategy that covers a topic with many focused pages, each answering one specific question, instead of one giant all-in-one guide. See what ranch-style SEO is.
Semantic search
Search engines understanding the meaning and context of a search, rather than just matching the exact words.
On-page SEO and content
On-page SEO
Improving the content and HTML of individual pages, such as titles, headings, copy and internal links. The on-page SEO checklist covers it step by step.
Title tag
The HTML title of a page, usually shown as the clickable headline in search results. Keep it specific and under about 60 characters.
Meta description
The short summary that can appear under your title in search results. It doesn’t affect rankings directly, but a good one earns more clicks.
Meta tags
HTML tags in a page’s head section that describe the page to browsers and search engines, such as the title, the meta description and the robots tag.
Meta keywords tag
An old HTML tag for listing a page’s keywords. Google has ignored it for many years, so there’s no need to fill it in.
Headings (H1, H2, H3)
The main title on a page (H1) and the subheadings that structure it (H2, H3 and so on). Clear headings help readers, search engines and AI tools follow the page.
URL slug
The readable part of a web address that identifies a page, like /seo-glossary/. Short, descriptive slugs are best.
Alt text
A short text description of an image, read by screen readers and used by search engines to understand the image.
Internal link
A link from one page on your site to another. Internal links help visitors and search engines find pages and understand which ones matter most.
Anchor text
The clickable words in a link. Descriptive anchor text tells readers and search engines what the linked page is about.
Above the fold
The part of a page visible without scrolling. It should make clear, quickly, that the visitor is in the right place.
E-E-A-T
Experience, expertise, authoritativeness and trust: the qualities Google’s quality rater guidelines use to describe helpful, reliable content. Trust matters most.
YMYL (Your Money or Your Life)
Topics that could affect someone’s health, finances, safety or wellbeing. Google holds these pages to a higher standard of trust.
Helpful content
Google’s term for content made to genuinely help people rather than to rank. Its assessment of helpfulness is now part of Google’s core ranking systems.
Thin content
Pages with little original or useful information, such as near-empty location pages or copied product descriptions.
Duplicate content
The same or very similar content at more than one URL. Google rarely penalizes it, but it splits signals between pages and can cause the wrong version to rank.
Content refresh
Updating an existing page with new information, better answers or clearer structure, often a faster win than writing something new.
Technical SEO
Technical SEO
Making sure search engines can crawl, render and index your site efficiently: speed, site structure, redirects, structured data and clean code. See the technical SEO guide.
Crawler
A program that discovers and downloads web pages by following links. Also called a bot or spider.
Googlebot
Google’s crawler. Bing’s equivalent is Bingbot.
Crawling
Search engines discovering pages by following links and reading sitemaps.
Crawl budget
Roughly how many pages a search engine will crawl on your site in a given period. It mainly matters for very large sites.
Rendering
A search engine running a page’s code to see its final content and layout, which matters most for JavaScript-heavy sites.
Indexing
A search engine storing a page so it can appear in results. Crawled doesn’t always mean indexed.
Index
The search engine’s database of the pages it can show in results.
Noindex
A tag or HTTP header that tells search engines not to show a page in their results.
robots.txt
A file at the root of your site that tells crawlers which parts of the site they shouldn’t crawl. It controls crawling, not indexing.
XML sitemap
A file listing the pages you want search engines to find, usually at /sitemap.xml.
Canonical tag
A tag telling search engines which version of similar or duplicate pages is the main one to show.
301 redirect
A permanent redirect from one URL to another. It sends visitors and search engines to the new page and passes along the old page’s ranking signals.
302 redirect
A temporary redirect. Use it only when the original URL is coming back.
Redirect chain
Several redirects in a row before reaching the final page. They slow down visitors and crawlers, so point old URLs straight to the final destination.
404 error
The “page not found” response. It’s normal for pages that no longer exist, but links on your own site should never point to one.
Soft 404
A page that looks like an error or is nearly empty but tells search engines it loaded successfully, which confuses them.
Orphan page
A page that no other page on your site links to, which makes it hard for visitors and search engines to find.
Site architecture
How your pages are organized and linked together, from the homepage down. Good architecture keeps important pages within a few clicks of the homepage.
Breadcrumbs
The trail of links (Home > Blog > SEO 101) showing where a page sits on your site. They help visitors and search engines understand your structure.
HTTPS
The secure version of HTTP, shown by the padlock in your browser. It’s a basic expectation for every site and a light ranking signal.
Mobile-first indexing
Google crawling and evaluating your site mainly as a phone sees it. If something is missing on mobile, Google may not see it at all.
Page speed
How quickly a page loads and responds. Slow pages lose visitors before they lose rankings.
Core Web Vitals
Google’s page experience metrics: Largest Contentful Paint for loading (good is 2.5 seconds or less), Interaction to Next Paint for responsiveness (200 milliseconds or less) and Cumulative Layout Shift for visual stability (0.1 or less).
Structured data (schema markup)
Code that labels the content on a page, such as your business details, products, reviews or FAQs, so search engines and AI tools can understand it reliably.
Schema.org
The shared vocabulary that structured data uses, supported by Google, Bing and other search engines.
JSON-LD
The format Google recommends for structured data: a small block of code in the page that describes its content.
hreflang
A tag that tells search engines which language or regional version of a page to show, such as en-CA or fr-CA. The guide to SEO in Canada explains when you need it.
JavaScript SEO
Making sure content that depends on JavaScript can still be rendered and indexed. Sending complete HTML from the server is the safest approach for both search engines and AI crawlers.
Log file analysis
Reviewing your server’s logs to see exactly which pages search engine and AI bots request, and how often.
Faceted navigation
The filters on e-commerce category pages, such as size, colour and price. Uncontrolled, they can create thousands of near-duplicate URLs.
Site migration
Moving a site to a new domain, platform or URL structure. Without careful redirects it’s the fastest way to lose rankings; see the SEO migration checklist.
Links and authority
Backlink
A link from another website to yours. Relevant, editorial backlinks are one of the strongest signals of trust.
Link building
Earning links from other websites through outreach, PR, partnerships and content worth citing.
Referring domain
A website that links to yours. Ten links from the same site count as one referring domain, which is why tools report both numbers.
Followed link
A normal link that can pass ranking value. “Dofollow” is SEO slang for the same thing; there’s no actual dofollow attribute.
Nofollow
A link attribute (rel="nofollow") asking search engines not to treat the link as an endorsement. rel="sponsored" marks paid links and rel="ugc" marks user-generated content such as comments.
PageRank
Google’s original method of measuring a page’s importance from the links pointing to it. Google stopped showing public PageRank scores in 2016, but links still matter.
Link equity
The ranking value a link passes from one page to another. Sometimes called “link juice”.
Domain authority
A general term for third-party scores that estimate a site’s link strength, such as Moz’s Domain Authority, Ahrefs’ Domain Rating and Semrush’s Authority Score. They’re useful for comparison, but none is a Google metric.
Link scheme
Buying, selling or trading links at scale to manipulate rankings. It breaks Google’s spam policies.
Disavow
Asking Google to ignore specific links to your site through Search Console. Most sites never need it; it’s mainly for cleaning up after a manual action.
Unlinked mention
Your business named on another site without a link. It’s often easy to turn into a link, and it helps AI tools recognize you even without one.
Guest post
An article you write for another website. Fine for reaching a new audience, but risky when done at scale purely for links.
Digital PR
Earning media coverage, links and mentions through newsworthy stories, data and expert commentary.
Local SEO
Local SEO
Improving your visibility for searches with local intent, especially in Google Maps and the map pack. The local SEO guide covers it in depth.
Google Business Profile
Your free business listing on Google Search and Maps, and the most important local SEO asset.
Map pack
The map and top three local businesses shown for searches with local intent. Also called the local pack.
Relevance, distance and prominence
The three things Google says determine local results: how well you match the search, how far you are from the searcher, and how well known and well reviewed you are.
Citation
An online listing of your business name, address and phone number, with or without a link.
NAP
Name, address, phone. Keeping them identical everywhere they appear helps local rankings.
Service-area business
A business that serves customers at their location, such as a plumber or cleaner. It can hide its address on Google and show a service area instead.
Apple Business Connect and Bing Places
The business listing tools for Apple Maps and Bing. They’re free, and often ignored by competitors.
Local rank tracking
Checking map rankings from many points across a town or city, often shown as a grid, because local results change with the searcher’s location.
Analytics and reporting
Google Search Console
Google’s free tool that shows the searches you appear for, your clicks and impressions, indexing problems and any manual actions.
Google Analytics 4 (GA4)
Google’s free analytics platform for tracking visitors, where they come from and what they do on your site.
Impressions
How many times your page appeared in search results, whether or not anyone clicked.
Clicks
How many times searchers clicked through to your site from the results.
Click-through rate (CTR)
The percentage of impressions that turned into clicks. A low CTR with high impressions usually means your title or description needs work.
Average position
The average ranking of your pages for the searches shown in Search Console. It’s an average across many searches, so read it alongside impressions.
Organic traffic
Visitors who arrive from unpaid search results.
Conversion
A visitor doing something valuable, such as calling, booking, filling in a form or buying. GA4 calls these key events.
Engagement rate
In GA4, the share of visits that lasted more than 10 seconds, viewed two or more pages, or included a key event. Bounce rate is the opposite: the share that didn’t.
Rank tracking
Monitoring where your pages rank for chosen keywords over time.
Share of voice
Your visibility across a set of keywords, or AI prompts, compared with your competitors.
AI search
AI Overview
Google’s AI-generated summary at the top of some search results, with links to its sources. AI Overviews have appeared in Canada since October 2024.
AI Mode
Google’s conversational search mode for more complex questions, with follow-up questions and links to sources. It launched in Canada in August 2025.
Answer engine optimization (AEO)
Structuring content so it’s chosen as the direct answer in featured snippets, voice results and AI Overviews. See answer engine optimization.
Generative engine optimization (GEO)
Improving how often AI assistants like ChatGPT, Gemini, Claude and Perplexity mention and cite your business. See generative engine optimization.
LLMO (large language model optimization)
Another name for optimizing for AI answers. It overlaps almost entirely with GEO, and you’ll also hear “AI SEO”.
LLM (large language model)
The type of AI model behind tools like ChatGPT, Claude and Gemini.
AI citation
A link to, or mention of, your page inside an AI-generated answer.
Entity
A clearly identifiable thing, such as a business, person or place, that search engines and AI models can recognize and connect facts to.
Knowledge Graph
Google’s database of entities and the connections between them. It powers knowledge panels.
AI crawler
A bot that collects web content for AI products. Examples include GPTBot (OpenAI’s training crawler), OAI-SearchBot (ChatGPT search), ClaudeBot and PerplexityBot. Google-Extended is a robots.txt setting that controls whether Google can use your content for its Gemini models.
Grounding
An AI tool basing its answer on web pages it retrieves at the time, rather than only on what it learned in training. Grounded answers are where citations come from.
Query fan-out
When an AI search tool breaks one question into many related searches behind the scenes and combines the results. It’s why long, prompt-like queries now show up in Search Console.
Prompt tracking
Regularly checking how AI assistants answer a set of questions about your category, and whether they mention you.
Hallucination
An AI answer that sounds confident but is wrong, such as outdated hours or prices for your business. Consistent information across the web makes it less likely.
llms.txt
An emerging, optional file that gives AI tools a plain-text map of your site. Support is still limited, so treat it as a nice-to-have.
Google’s rules, updates and penalties
Google Search Essentials
Google’s published rules for appearing in search, including its spam policies. They were formerly called the Webmaster Guidelines.
Core update
A broad change to Google’s ranking systems, rolled out several times a year. Rankings often shift for weeks afterwards.
Spam policies
The practices Google treats as manipulation, such as link schemes, cloaking, keyword stuffing and scaled content abuse. Breaking them can lead to lower rankings or removal.
Manual action
A penalty applied by a human reviewer at Google. It appears in Search Console with the reason and the steps to fix it.
Penalty
An informal term for lost rankings. Strictly, only manual actions are penalties; most drops come from algorithm updates or competitors improving.
White hat SEO
SEO that follows search engines’ rules and focuses on genuinely useful pages and earned links. Black hat SEO is the opposite: shortcuts that break the rules and tend to fail.
Cloaking
Showing search engines different content from what visitors see. It’s a clear spam policy violation.
Scaled content abuse
Producing large numbers of pages mainly to rank rather than to help people, whether written by AI or by hand. It’s one of Google’s spam policies.
Doorway pages
Pages built to rank for very similar searches, often just swapping in a different city name, that add nothing unique. Google treats them as spam.
Google sandbox
A popular belief that Google holds new sites back for months. Google says there’s no sandbox, but new sites do take time to earn trust and links.
SEO terms people often mix up
SEO vs SEM: SEO earns unpaid rankings; SEM usually means paid search ads. They’re not interchangeable, although some people use SEM to cover both.
Crawling vs indexing: Crawling is finding and reading a page; indexing is storing it so it can appear in results. A page can be crawled and still not be indexed.
Noindex vs robots.txt: A noindex tag keeps a page out of search results. Blocking a page in robots.txt only stops crawling, so the URL can still appear in results, and Google can’t see a noindex tag on a page it isn’t allowed to crawl.
301 vs 302 redirect: A 301 is permanent and moves the page’s signals to the new URL; a 302 is temporary and tells search engines the original is coming back.
Canonical tag vs redirect: A redirect sends everyone to a new URL. A canonical tag leaves both URLs working but tells search engines which one to show in results.
AEO vs GEO: AEO is about being the direct answer to a question; GEO is about being mentioned and cited by AI assistants. In practice they overlap, as the SEO vs AEO vs GEO guide explains.
SEO acronyms and abbreviations
| Acronym | Stands for | In plain English |
|---|---|---|
| AEO | Answer engine optimization | Being chosen as the direct answer |
| CLS | Cumulative Layout Shift | How much a page jumps around while loading |
| CMS | Content management system | The software you edit your site in, like WordPress or Webflow |
| CPC | Cost per click | What an ad click costs; also a sign of a keyword’s commercial value |
| CRO | Conversion rate optimization | Getting more visitors to take action |
| CTA | Call to action | The button or link asking visitors to do something |
| CTR | Click-through rate | The share of impressions that become clicks |
| CWV | Core Web Vitals | Google’s loading, responsiveness and stability metrics |
| DA / DR | Domain Authority / Domain Rating | Third-party link strength scores from Moz and Ahrefs |
| E-E-A-T | Experience, expertise, authoritativeness, trust | What makes content credible |
| GA4 | Google Analytics 4 | Google’s analytics platform |
| GBP | Google Business Profile | Your listing on Google Search and Maps |
| GEO | Generative engine optimization | Getting mentioned and cited by AI assistants |
| GSC | Google Search Console | Google’s free search performance tool |
| GTM | Google Tag Manager | A tool for managing tracking code |
| HTML | HyperText Markup Language | The code web pages are built with |
| HTTPS | Hypertext Transfer Protocol Secure | The secure, padlocked version of a web address |
| INP | Interaction to Next Paint | How quickly a page responds when you tap or click |
| KD | Keyword difficulty | How hard a keyword is to rank for |
| KPI | Key performance indicator | The number you judge success by |
| LCP | Largest Contentful Paint | How quickly the main content loads |
| LLM | Large language model | The AI model behind ChatGPT, Claude and Gemini |
| LLMO | Large language model optimization | Another name for GEO |
| NAP | Name, address, phone | Your core business details |
| PAA | People Also Ask | The box of related questions in results |
| PPC | Pay per click | Ads you pay for each time someone clicks |
| ROI | Return on investment | What you get back for what you spend |
| SEM | Search engine marketing | Usually means paid search ads |
| SEO | Search engine optimization | Earning unpaid search visibility |
| SERP | Search engine results page | The page of results after a search |
| SSL / TLS | Secure Sockets Layer / Transport Layer Security | The encryption behind HTTPS |
| SSR | Server-side rendering | Sending complete HTML so bots don’t need to run JavaScript |
| UGC | User-generated content | Reviews, comments and forum posts |
| URL | Uniform Resource Locator | A web address |
| UX | User experience | How easy and pleasant a site is to use |
| YMYL | Your Money or Your Life | Topics held to a higher standard of trust |
Putting the vocabulary to work
Knowing the terms is the first step; knowing which ones matter for your site is the next. Run your site through the free SEO grader to see how it does on the fundamentals, read SEO vs AEO vs GEO for the bigger picture, or see how I approach SEO.