SEO Terms, Explained

SEO has an unusual amount of vocabulary for a field with so few confirmed facts. This page defines about fifty terms in one or two sentences each, and tells you which ones are Google's, which are industry shorthand, and which were invented by somebody with something to sell.

How to read the third column

Every table below has a Whose term column, because this is where most confusion in SEO actually comes from. A number published by Google and a number modelled by a tool vendor look identical in a report, and they are not the same kind of thing at all.

• Google - Google's own term, metric, or documented policy. You can go and read the definition on their site.
• Standard - a web standard or shared specification that predates or sits outside Google.
• Industry - useful shorthand the SEO field made up. Real concept, no official definition, so different people mean slightly different things by it.
• Vendor - a specific company's product, presented as a measurement. Treat as an estimate, never as a fact.
• Myth - a term with no mechanism behind it. Safe to ignore, and slightly useful as a signal about whoever used it.

The results page

Term	What it means	Whose term
SERP	Search engine results page: everything you see after hitting enter, ads and features included. Reading one properly is the most useful two minutes in SEO.	Industry
Organic result	A result you did not pay for, ranked by the algorithm. The "ten blue links", though there are rarely ten any more.	Industry
SERP feature	Any block on the page that is not a plain organic result: snippets, maps, videos, images, questions.	Industry
Featured snippet	A boxed answer at the top, lifted from a page that already ranks. Winning one can raise your visibility and lower your clicks at the same time.	Google
People Also Ask (PAA)	The expandable list of related questions. The best free source of subheadings and article ideas on the internet.	Google
AI Overview	Google's generated summary above the results, which cites sources rather than linking ten of them.	Google
Local pack	The map with three business listings. Won with a Business Profile and reviews, not with articles.	Industry
Knowledge panel	The side box of facts about an entity: a company, a person, a film. Populated from Google's own knowledge graph.	Google
Sitelinks	The extra sub-links shown under a result. Not requestable; Google generates them when it understands your site structure.	Google
Rich result	A result with extra visual detail such as star ratings, prices, or FAQ dropdowns, earned through structured data.	Google

Keywords and demand

Term	What it means	Whose term
Keyword	Any phrase somebody typed into a search box. Mostly full questions now, which makes the word a bit of a fossil. More here.	Industry
Head term	A short, high-volume, high-competition phrase such as tax software. Broad intent, expensive to win.	Industry
Long tail	Longer, more specific phrases with less volume each and far more of them in total. Where small sites usually win.	Industry
Search volume	Estimated average monthly searches, modelled from sampled data and rounded. An order of magnitude, not a count.	Vendor
Keyword difficulty (KD)	A 0-100 estimate of how hard a keyword looks to rank for, based mostly on the link profiles of pages currently ranking. Google publishes nothing like it, and two tools will disagree by 20 points.	Vendor
CPC	Cost per click: what advertisers actually bid for that search. The only number in a keyword row grounded in somebody's real money, which makes it the best proxy for commercial value.	Google
Search intent	What the searcher wants to happen next: learn, navigate, compare, or buy. The four types. Google's own rater vocabulary is different again (Know, Do, Website, Visit-in-person).	Industry
Seed keyword	A short starting phrase used to discover related ones. Feed a tool a sentence instead of a seed and you get nothing back.	Industry
Striking distance	Pages ranking roughly 11 to 30: close enough that one improvement can push them onto page one. The highest-return list on most sites.	Industry
Zero-volume keyword	A phrase a tool reports as 0, which almost always means "below what our sample can see" rather than nobody asks it.	Industry
Cannibalization	Two or more of your own pages competing for the same query, so neither accumulates the signals to win it. How to confirm and fix it.	Industry
LSI keywords	Supposedly semantically related terms Google looks for. Latent semantic indexing is a real 1980s technique that does not scale to the web and that Google does not use. The instinct (cover the topic fully) is fine; the term is not.	Myth

Structure and internal organization

Term	What it means	Whose term
Pillar page	The broad hub page for a subject, linking out to the detailed pages beneath it. Pillars and clusters explained.	Industry
Cluster	A group of keywords that want the same page, or a group of pages covering one sub-topic together. Best decided from shared search results rather than from how similar the words look.	Industry
Topical authority	The idea that covering one subject completely beats scattering posts across many. The depth argument.	Industry
Internal link	A link from one page of your site to another. The only links you fully control, and usually the cheapest fix available.	Industry
Anchor text	The clickable words of a link. They tell both readers and search engines what the destination is about, which is why "click here" wastes one.	Industry
Orphan page	A page with no internal links pointing at it. Hard to find, rarely crawled, effectively invisible.	Industry
Thin content	A page with little or no added value for the reader. Note that "thin" is about substance, not length; a 200-word answer can be complete.	Google
Duplicate content	The same information on more than one URL. There is no penalty for it; Google picks one version to show and filters the rest.	Google

Crawling, indexing, and files

Term	What it means	Whose term
Crawl	Googlebot fetching a page. Finding it comes first, usually via a link or a sitemap.	Google
Index	The store of pages Google considers eligible to show. Being indexed is a precondition for ranking, not a reward.	Google
Crawl budget	Roughly how much crawling Google will spend on your site. A genuine concern above a hundred thousand URLs and a distraction below it.	Google
Rendering	Running a page's JavaScript to see the final content. Matters when your text only exists after scripts run.	Google
Sitemap	An XML file listing your URLs, submitted once in Search Console. It helps discovery; it does not make anything rank.	Standard
robots.txt	A file telling crawlers which paths not to fetch. It does not remove pages from the index, and blocking a page you also want deindexed backfires.	Standard
noindex	A tag telling search engines not to keep this page in the index. The correct tool for the job robots.txt cannot do.	Google
Canonical	A tag naming the preferred URL when several show the same content. A hint, not a command; Google can choose differently.	Google
hreflang	Markup declaring which language and region a page is for, so Google shows the German version to German searchers. Easy to get wrong, and it must be reciprocal.	Google
Soft 404	A page that says "not found" to the reader while returning a success code to the crawler. Confusing to Google and worth fixing properly.	Google

The numbers in Search Console

Term	What it means	Whose term
Impression	Your page appeared in results for a query. It does not mean anybody scrolled far enough to see it.	Google
Click	Somebody clicked through to your site from search. The only number here that produced a visitor.	Google
CTR	Clicks divided by impressions. Most useful as a comparison against your own other pages at similar positions, never against a published benchmark.	Google
Average position	The mean position of your page across all impressions for a query. An average of very different situations, so treat sudden moves with suspicion.	Google
Query count	How many distinct searches you appear for. Growth here is the earliest honest sign that a site is gaining ground.	Industry
Bounce rate	An analytics measure of single-page visits. Not a Google ranking input, and a fast answer that ends the visit is a success, not a failure.	Vendor
Dwell time	How long a searcher stays before returning to results. An industry coinage: nobody outside Google can measure it and no tool genuinely reports it.	Industry

Measuring Results in Search Console: The Four Numbers That Matter→

Links and authority

Term	What it means	Whose term
Backlink	A link from someone else's site to yours. Still a signal, and no longer the constraint most small sites think it is. The honest version.	Industry
Referring domain	One distinct website linking to you, however many links it sends. A better thing to count than raw link totals.	Industry
nofollow, sponsored, ugc	Link attributes marking paid, user-generated, or untrusted links. Since 2019 Google treats them as hints rather than absolute instructions.	Google
PageRank	The original link-counting algorithm. A descendant still runs internally; the public toolbar score was retired in 2016.	Google
Link equity	Informal name for the ranking value a link passes. Useful mental model, no published mechanism, and "link juice" means the same thing with less dignity.	Industry
DA, DR, Authority Score	Moz, Ahrefs, and Semrush scores out of 100, each built from that company's own crawl. Good for comparing SERPs at a glance, useless as targets. Why.	Vendor
Disavow	A Search Console tool for telling Google to ignore links to your site. Most sites should never touch it, because junk links are already discounted.	Google

Quality, trust, and AI search

Term	What it means	Whose term
E-E-A-T	Experience, Expertise, Authoritativeness, Trust: concepts from Google's quality rater guidelines. There is no E-E-A-T score in the algorithm. What it means for a small site.	Google
YMYL	"Your Money or Your Life": topics where bad information causes real harm, such as health, finance, and law. The quality bar is genuinely higher here.	Google
Helpful content	Google's framing for content made for people rather than for rankings. The standalone system was folded into core ranking in March 2024, so there is no separate update to wait for.	Google
Core update	A broad, announced change to Google's ranking systems, rolled out over weeks. Not a penalty; a re-assessment of everything at once.	Google
Manual action	A human reviewer at Google penalising your site, reported in Search Console with a reconsideration process. Rare, and the only kind of penalty you can actually see.	Google
Scaled content abuse	The spam policy covering many pages generated mainly to manipulate rankings rather than help users, no matter how they were created. Where the real risk sits.	Google
Structured data	Machine-readable markup describing what a page is about, using the shared schema.org vocabulary. Sometimes earns a rich result, always aids machine understanding.	Standard
AEO / GEO	Answer Engine Optimization or Generative Engine Optimization: recent coinages for making content quotable by AI answers. Real shift, contested names, no agreed definition yet. How AI search reads content.	Industry
Core Web Vitals	Three page-experience metrics: LCP (loading), CLS (layout stability), INP (responsiveness, which replaced FID in March 2024). A confirmed signal and a small one.	Google

The six worth actually understanding

You can skim the rest. If you only internalise a handful, make it these, because each one changes a decision rather than a vocabulary.

• Search intent - decides whether your article can rank at all, before quality enters the conversation.
• Striking distance - the cheapest wins on any site over six months old are already sitting at positions 11 to 30.
• Cluster - the difference between two articles and one, decided by evidence rather than by how similar the phrases look.
• Impressions versus clicks - impressions tell you Google is considering you, clicks tell you readers chose you. They move at different times and mean different things.
• Cannibalization - the most common self-inflicted ranking problem, and invisible unless you go looking.
• Keyword difficulty - specifically, understanding that it is a vendor's model of a SERP and not a property of your site.

Jargon in this field is mostly a compression device, and occasionally a costume.

SEO Myths That Waste Your Time→ What a Keyword Really Is→ Reading a SERP: A Walkthrough→