SEO Terms, Explained in Plain English

Every industry has its own vocabulary, and SEO has more than its share. This glossary explains every term you are likely to hear, starting with the handful that actually matter to a business owner and working down toward the deep technical language your agency uses with its engineers.

Read the first section and you will understand ninety percent of any conversation about your website's visibility. Keep going and you will understand the other ten percent better than most people who do this for a living. Every term links to a deeper explanation wherever we have written one.

Level 1. SEO 101: the twenty terms that actually matter

If you read nothing else on this page, read this section. These twenty terms cover almost every conversation you will have about getting your business found on Google. Everything below this section is detail layered on top of these ideas, so there is no shame in stopping here and coming back later.

Think of it this way. Google is a librarian with an impossibly large library. It has to find your book, decide what your book is about, judge whether your book is any good, and then decide whether to hand it to the person standing at the desk. Almost every term in SEO describes one of those four steps.

That is the working vocabulary. If someone uses a word outside this list and cannot immediately explain why it matters to your revenue, you are allowed to be suspicious.

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Level 2. Getting found locally

Local search runs on a different set of rules than the rest of Google. A national brand competes on authority and content volume. You compete on three things Google weighs specifically for local queries: how close you are to the searcher, how well you match what they asked for, and how well known you are. The terms below are the machinery behind those three ideas.

The short version is that Google is trying to answer one question about your business: are you real, and are you here? Everything in this section is a way of proving it.

Level 3. On-page and content terms

On-page SEO used to mean repeating your keyword until the page read like a ransom note. That era is over. Modern search engines convert your writing into mathematical representations of meaning, so the goal now is clarity of subject rather than density of keyword.

This section covers what lives on the page itself, plus the vocabulary search engines use to describe topics and how they relate to one another.

Level 4. How Google actually finds your site

Here is where the vocabulary gets technical, and here is the honest reason it matters: most sites that "cannot rank" do not have a content problem. They have a plumbing problem. Google is being actively told not to look, or is being sent in circles, and nobody noticed.

Every term below describes either a way Google discovers a page, or a way you accidentally told it not to. If your traffic dropped without warning, the cause is almost always in this section. This is the work our technical SEO team does first on every engagement.

Level 5. Speed and Core Web Vitals

Google measures how your site feels to real people using real phones on real connections, and it uses those measurements as a ranking input. The data comes from actual Chrome users, not from a lab test, which is why your developer's local test can look perfect while your scores are poor.

Three metrics carry the weight. Everything else in this section is a diagnostic that explains why one of those three is failing. Fixing them is the core of our website optimization work.

The three thresholds that matter:

Level 6. Links and authority

Google began as a citation-counting machine. Its founding insight was that a link from one site to another works like an academic citation: a vote of confidence you cannot easily fake. Twenty-five years and a great deal of spam later, the system is far more suspicious, but the principle holds.

You do not need to understand the mathematics. You need to understand that links from relevant, respected, real websites raise your standing, links you buy or manufacture eventually cost you, and the links between your own pages are yours to control for free. That last one is where most sites leave money on the table.

Level 7. AI search: GEO, AEO, and answer engines

This is the part of the industry that changed fastest, and it is where most of the new vocabulary is coming from. The shift is simple to state. Search engines used to hand you a ranked list of places to go. Increasingly they hand you an answer, with a few small citations underneath it.

That changes the goal. Ranking in position three is worth less if the searcher never scrolls past a summary that answered their question. The new objective is to be the source that summary is built from. We cover the practical side of this in our Kansas City guide to AI search, and it is the core of our generative engine optimization service.

Level 8. Under the hood: what the Google leak revealed

In 2024, internal Google documentation describing thousands of ranking-related attributes became public, and antitrust testimony filled in more. None of it is a manual, and none of it changes what you should do on Monday morning. It is worth knowing because it settles several arguments the industry had been having for a decade.

Two findings matter to a business owner. First, Google does watch what people do after they click, and it does adjust rankings accordingly. Second, Google tracks how tightly focused a site is on its subject, and wandering off-topic has a measurable cost. Everything below is detail on those two points.

How a search request moves through the system:

1. Ingestion. A crawler called Trawler fetches documents into storage systems named Alexandria and SegIndexer.
2. Primary scoring. A cluster called Mustang, running an algorithm called Ascorer, produces an initial relevance score from text and links.
3. Re-ranking. Functions called Twiddlers adjust those scores for freshness, quality, and variety.
4. Behavioral validation. NavBoost re-scores results using what real users clicked and how long they stayed.
5. Delivery. SuperRoot and Glue assemble the final page you see.

Level 9. Measuring it: the results page and your analytics

The last set of terms covers how you tell whether any of this is working. Two things trip people up here. First, Google Search Console and Google Analytics measure different things and will never agree, and that is correct behavior rather than a bug. Second, in an era of AI answers and zero-click searches, traffic alone has stopped being a complete measure of visibility.

These are the terms you will see on every report we send, and what each one is actually telling you. Our approach to analytics and reporting is built around tying them back to revenue rather than to vanity numbers.

The A-to-Z quick reference

Every term on this page, alphabetized, with a one-line definition and the level where it is explained in full. Use your browser's find function to jump straight to what you heard.

Numbers and symbols

• 200 OK — The page loaded normally. (Level 4)
• 301 redirect — A permanent move that passes ranking value to the new address. (Level 4)
• 302 redirect — A temporary move that keeps ranking value on the old address. (Level 4)
• 308 redirect — A permanent redirect that also preserves the request method. (Level 4)
• 404 Not Found — The page does not exist. (Level 4)
• 410 Gone — The page was deliberately removed for good. (Level 4)
• 500 Internal Server Error — Your server broke while responding. (Level 4)
• 503 Service Unavailable — Your server is temporarily down. The correct status for maintenance. (Level 4)

A

• AEO — Answer Engine Optimization. Writing concise answers built for AI extraction. (Level 7)
• Agent Experience (AX) — Designing your site for software agents, not only human eyes. (Level 7)
• Agentic commerce — AI agents researching and buying on a customer's behalf. (Level 7)
• AI citation — The source link inside an AI-generated answer. The new ranking position. (Level 7)
• AI Mode — Google's fully conversational search experience. (Level 7)
• AI Overview (AIO) — Google's AI-written summary above the organic results. (Level 1, Level 7)
• AI slop — Low-effort AI-generated content that search engines actively filter against. (Level 7)
• Alexandria — An internal Google storage layer holding indexed documents. (Level 8)
• Alt text — Descriptive text on an image, for screen readers and image search. (Level 3)
• Anchor mismatch — A demotion when link text contradicts the destination's topic. (Level 6)
• Anchor text — The visible, clickable words in a link. (Level 6)
• Answer engine — Any tool that answers directly instead of listing links. (Level 7)
• Ascorer — The algorithm producing Google's initial relevance score. (Level 8)
• Average position — Your mean ranking for a keyword over a period. (Level 9)

B

• BabyPanda — An internal content-quality classification system. (Level 8)
• Backlink — An incoming link from another website to yours. (Level 1, Level 6)
• badClicks — Clicks where the user immediately bounced back to search. (Level 8)
• BERT — A Google language model reading sentences in both directions for context. (Level 7)
• Black hat SEO — Tactics that deliberately violate search engine guidelines. (Level 6)
• Bounce rate — The retired metric for single-page visits. Replaced by engagement rate. (Level 9)
• Branded anchor — Link text that is simply your business name. The safest pattern. (Level 6)
• Breadcrumbs — The navigation trail showing where a page sits in your hierarchy. (Level 4)
• Broken link building — Finding dead links elsewhere and offering your page as the fix. (Level 6)

C

• Canonical tag — Names the one official version of a page that exists at several URLs. (Level 4)
• ccTLD — A country-code domain such as .co.uk. A strong geographic signal. (Level 4)
• CenterPiece — The system separating main content from headers, sidebars, and footers. (Level 8)
• Citation (local) — A mention of your name, address, and phone number on another site. (Level 2)
• Citation share of voice — How often AI tools cite you versus your competitors. (Level 7)
• Click depth — How many clicks from your homepage to a given page. (Level 4)
• Client-Side Rendering (CSR) — The browser builds the page from JavaScript. Hardest to index. (Level 5)
• CLS — Cumulative Layout Shift. How much the page jumps while loading. Target 0.1 or less. (Level 5)
• Coati — A successor to the Panda content-quality systems. (Level 8)
• Commercial investigation — Search intent where someone is comparing options before buying. (Level 3)
• Conceptual Depth Divergence — Long guides rank well but get cited by AI less often. (Level 7)
• Content collapse — Search results diluted by mass-produced synthetic content. (Level 7)
• Content Effort Score — An internal estimate of the real work invested in a page. (Level 8)
• Conversion — The action you actually want. The only number that ultimately matters. (Level 9)
• Core Web Vitals (CWV) — Google's three real-user performance measurements. (Level 5)
• Crawl budget — How many pages a search engine will fetch from you in a given period. (Level 4)
• Crawling — A search engine sending a program to read your pages. (Level 1, Level 4)
• Critical rendering path — The steps a browser must finish before showing anything. (Level 5)
• CrUX — Chrome User Experience Report. The real-user data behind Core Web Vitals. (Level 5)
• CTR — Click-Through Rate. Clicks divided by impressions. (Level 1, Level 9)

D

• Data aggregator — A company whose business records feed hundreds of directories. (Level 2)
• Deterministic search — The old model where identical queries return identical results. (Level 7)
• Disavow file — A request asking Google to ignore specific backlinks. A last resort. (Level 6)
• Dofollow — The default state of a link. It passes ranking value. (Level 6)
• DOM — Document Object Model. The browser's live internal structure of the page. (Level 5)
• Domain Authority / Domain Rating — Third-party 0-to-100 link strength scores. Not a Google metric. (Level 6)
• Duplicate content — The same text at more than one URL. A dilution problem, not usually a penalty. (Level 4)
• Dwell time — How long someone stays on your page before returning to search. (Level 8)

E

• E-E-A-T — Experience, Expertise, Authoritativeness, Trustworthiness. (Level 1)
• Engagement rate — GA4's measure of sessions that lasted, converted, or went deeper. (Level 9)
• Entity — A single, distinct, identifiable thing: a person, company, place, or product. (Level 3)
• Exact Match Domain (EMD) — A domain that is literally the keyword. Largely neutralized now. (Level 6)
• Exact-match anchor — Link text that is precisely your target keyword. High risk in volume. (Level 6)
• Explanatory bloat — Filler before the answer. It costs you AI citations. (Level 7)
• Explanatory Efficiency Index — The ratio of verifiable facts to total word count. (Level 7)

F

• Faceted navigation — Product filters that generate a new URL per combination. (Level 4)
• FCP — First Contentful Paint. When the first thing appears on screen. (Level 5)
• Featured snippet — The answer box at the top of results. Also called position zero. (Level 9)
• Feed resonance — Enriching a product feed with context and relationships, not just prices. (Level 7)
• FID — First Input Delay. Retired and replaced by INP. (Level 5)
• filetype: operator — Restricts a Google search to a file type, such as PDF. (Level 9)

G

• GA4 — Google Analytics 4. Measures what visitors do after they arrive. (Level 9)
• GBP — Google Business Profile. Your free listing powering Maps and the Local Pack. (Level 1, Level 2)
• GBP Posts — Short updates published directly to your Google listing. (Level 2)
• GEO — Generative Engine Optimization. Structuring content to be cited by AI systems. (Level 7)
• goodClicks — Clicks where the user stayed and appeared satisfied. (Level 8)
• Googlebot — The program Google sends to fetch and read your pages. (Level 4)
• Grey hat SEO — Tactics in the ambiguous space between white hat and black hat. (Level 6)
• GSC — Google Search Console. The only true source of search data about your site. (Level 9)

H

• H1 to H6 — The heading hierarchy that organizes a page's content. (Level 3)
• Hostage (Sandbox) — A mechanism limiting how visible a brand new domain can be. (Level 8)
• Hreflang — A tag mapping language and country versions of a page to each other. (Level 4)
• Hydration — JavaScript attaching interactivity to already-rendered HTML. (Level 5)

I

• Impression — One appearance of your page in search results. (Level 1, Level 9)
• Index bloat — Thousands of low-value URLs clogging the index. (Level 4)
• Indexing — Google storing a crawled page so it becomes eligible to rank. (Level 1, Level 4)
• Information gain — Whether your page adds anything not already available elsewhere. (Level 7)
• Informational intent — The searcher wants to learn something. (Level 3)
• INP — Interaction to Next Paint. Responsiveness to taps. Target 200 ms or less. (Level 5)
• Internal link — A link from one of your pages to another. Free and highly controllable. (Level 3)
• intitle: operator — Restricts a Google search to pages with a phrase in the title tag. (Level 9)
• inurl: operator — Restricts a Google search to URLs containing a given string. (Level 9)

J to K

• JSON-LD — The code format structured data is written in. (Level 3)
• Keyword — A word or phrase someone types into a search engine. (Level 1)
• Keyword cannibalization — Two of your own pages competing for the same search. (Level 3)
• Keyword density — The percentage of a page that is your keyword. An obsolete metric. (Level 3)
• Knowledge Graph — Google's database of entities and the facts connecting them. (Level 3)
• Knowledge Panel — The information card about a business or entity on a results page. (Level 9)

L

• lastLongestClicks — The result someone clicked last and stayed on longest. (Level 8)
• LCP — Largest Contentful Paint. When the main content appears. Target 2.5 seconds or less. (Level 5)
• Lighthouse — Google's free page auditing tool. Its score is not your ranking score. (Level 5)
• Link bait — Original research or tools built specifically to earn links naturally. (Level 6)
• Link equity (link juice) — The ranking value a link passes to its destination. (Level 6)
• Link farm — A site or network existing only to sell links. (Level 6)
• Link velocity — The rate at which you gain new backlinks. Spikes look purchased. (Level 6)
• Local intent — A search Google decides deserves a map, whether or not a city was typed. (Level 2)
• Local Pack — The map plus three business listings on local searches. (Level 1, Level 2)
• Local SEO — SEO aimed at customers searching near you. (Level 1)
• Log file analysis — Reading your server's raw record of every bot visit. (Level 4)
• LSI keywords — A misapplied industry term. Not a real Google system. (Level 3)

M to N

• Meta description — The summary shown under your title in search results. (Level 1, Level 3)
• MUM — Multitask Unified Model. Understands text, images, and audio together. (Level 7)
• Mustang — Google's primary scoring and retrieval cluster. (Level 8)
• Naked URL anchor — A link whose visible text is the raw web address. (Level 6)
• NAP — Name, Address, Phone number. The three facts identifying your business. (Level 1, Level 2)
• NavBoost — The system re-ranking results using real user click behavior. (Level 8)
• Navigational intent — The searcher wants a specific site or brand. (Level 3)
• Negative SEO — Someone aiming spam links at your site. Usually ignored automatically. (Level 6)
• noindex — An instruction telling search engines to drop a page from results. (Level 4)
• rel="nofollow" — Asks search engines not to pass value through a link. Now a hint. (Level 6)

O to P

• Omnimedia strategy — Coordinating text, video, audio, and data as one body of knowledge. (Level 7)
• On-page SEO — Everything you control on the page itself. (Level 1, Level 3)
• Organic results — The unpaid listings, ranked by merit. (Level 1)
• Orphan page — A live page nothing on your site links to. (Level 4)
• Out-of-stock handling — What to do with a product URL when inventory runs out. (Level 4)
• PageRank — The original algorithm scoring pages by the links pointing at them. (Level 6)
• Paid results — The ads marked "Sponsored." Instant but rented. (Level 1)
• Passage-level optimization — Structuring each section as a clear question and answer. (Level 7)
• PBN — Private Blog Network. Sites owned solely to link to a target. (Level 6)
• People Also Ask (PAA) — The expandable related questions on a results page. (Level 9)
• phraseAnchorSpamDays — Tracks sudden spikes in identical anchor text. (Level 8)
• Pillar page — One comprehensive page covering a broad subject end to end. (Level 3)
• Primary category — The single category describing your business in GBP. (Level 2)
• Probabilistic search — The new model where AI generates varying answers statistically. (Level 7)
• Programmatic SEO (pSEO) — Generating many pages from a database and a template. (Level 7)
• Prominence — How well known your business is. One of the three local pillars. (Level 2)
• Proximity — How near you are to the searcher. The local pillar you cannot change. (Level 2)

Q to R

• QDF — Query Deserves Freshness. Temporarily favors new content on surging topics. (Level 8)
• Query fan-out — An AI splitting one question into ten to twenty sub-questions. (Level 7)
• RAG — Retrieval-Augmented Generation. The AI fetches real documents, then writes. (Level 7)
• Ranking — Your position in the organic results for a keyword. (Level 1)
• Referring domain — A unique website linking to you, however many links it sends. (Level 6)
• Relevance (local) — How well you match what was searched. One of the three local pillars. (Level 2)
• Relevance Engineering (r19g) — Aligning content with how AI retrieval systems select sources. (Level 7)
• Render-blocking resource — A file that stops the page displaying until it downloads. (Level 5)
• Review recency — How recently your latest reviews were posted. (Level 2)
• Rich result — An enhanced listing with stars, prices, images, or dropdowns. (Level 3)
• robots.txt — A root file telling crawlers which folders they may not enter. (Level 4)
• Robots meta directive — Page-level instructions for search engines. (Level 4)

S

• Schema markup — Invisible code declaring exactly what a page is. (Level 1, Level 3)
• Schema.org — The shared vocabulary structured data uses. (Level 3)
• Search intent — What the searcher actually wants. (Level 1, Level 3)
• Search Quality Rater Guidelines — Google's public manual for its human evaluators. (Level 8)
• SegIndexer — An internal Google index storage layer. (Level 8)
• Semantic chunk — A passage that answers one question without needing the rest of the page. (Level 7)
• Semantic triple — A fact stated as subject, predicate, object. (Level 7)
• SEO — Search Engine Optimization. (Level 1)
• SERP — Search Engine Results Page. (Level 1)
• SERP features — Everything on a results page that is not a plain organic listing. (Level 9)
• Server-Side Rendering (SSR) — The server sends complete HTML. Reliable for crawlers. (Level 5)
• Service area — The geography you tell Google you serve. (Level 2)
• site: operator — Lists the pages Google has indexed for a domain. (Level 9)
• siteFocusScore — How tightly your whole site sticks to one subject. (Level 8)
• Sitelinks — Extra sub-page links under a brand's main result. (Level 9)
• siteRadius — How far an individual page strays from your core subject. (Level 8)
• smallPersonalSite — A flag identifying independent blogs and small sites. (Level 8)
• Soft 404 — Says "not found" to people but reports 200 OK to machines. (Level 4)
• SpamBrain — Google's system for identifying and devaluing manipulative links. (Level 6)
• Speed Index — How quickly the visible page fills in. A lab score. (Level 5)
• rel="sponsored" — Marks a paid, affiliate, or advertising link. (Level 6)
• Static Site Generation (SSG) — Pages pre-built as files. Fastest and most crawl-friendly. (Level 5)
• Structured citation — A formal directory listing such as Yelp or the BBB. (Level 2)
• Structured data — Code declaring your page's facts unambiguously. (Level 3)

T to Z

• TBT — Total Blocking Time. How long scripts froze the browser during load. (Level 5)
• TeraGoogle — An internal Google index storage layer. (Level 8)
• Three-tier AI measurement — Measuring extractability, AI citations, and revenue together. (Level 7)
• Title tag — The clickable headline for your page in search results. (Level 1, Level 3)
• Topic cluster — A pillar page plus supporting pages, all interlinked. (Level 3)
• Topical authority — Reputation for covering a subject thoroughly. (Level 3)
• Transactional intent — The searcher is ready to act now. (Level 3)
• Trawler — Google's internal crawling and fetching system. (Level 8)
• TTFB — Time to First Byte. How fast your server starts responding. (Level 5)
• Twiddler — A function that re-ranks results after initial scoring. (Level 8)
• rel="ugc" — Marks links inside user-generated content such as comments. (Level 6)
• Unstructured citation — A casual mention in a news story or blog post. (Level 2)
• Vector embeddings — Numerical representations of meaning. Why topic beats keyword. (Level 3)
• White hat SEO — Tactics aligned with search engine guidelines. (Level 6)
• X-Robots-Tag — Indexing instructions delivered in the server header. (Level 4)
• XML sitemap — A machine-readable list of pages you want indexed. (Level 4)
• YMYL — Your Money or Your Life. Topics held to stricter quality standards. (Level 3)
• Zero-click search — A search that ends without anyone clicking through. (Level 7)

What to do with all of this

You do not need to memorize any of it. The value of a glossary is that it exists when you need it, and that it lets you ask better questions.

Here is the honest summary of two hundred terms. Make sure Google can reach your pages. Make sure each page clearly answers one real question. Make sure your business information is identical everywhere it appears. Earn mentions from real places. Then measure whether any of it produced a phone call.

If something on this page described a problem you recognize on your own site, that is worth knowing about now rather than after another quarter of lost traffic. We run a free visibility audit for Kansas City businesses that checks the technical items in Level 4, the local signals in Level 2, and whether AI tools are currently citing you or a competitor.

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Where this comes from

The technical definitions here draw on public search engine documentation, the 2024 Google Content API Warehouse leak and the antitrust testimony that accompanied it, and The AI Search Manual by Michael King and the iPullRank team, which is the source for the Relevance Engineering material in Level 7. Everything has been rewritten in plain English. Any mistakes in that translation are ours.