SEO Terminology Guide: Plain-English Glossary

Overview

This SEO terminology guide is a practical reference you can use to align teams and make better search decisions. You’ll get 40–60 word, snippet-ready definitions, quick “X vs Y” decision rules, JavaScript SEO basics, and an A–Z appendix. It’s built for marketing managers, founders, content leads, and junior SEOs.

Use it to look up a term fast, then scan the example to see how it applies. Where accuracy matters, we link to primary sources like Google and standards bodies. You’ll also find fresh coverage on AI Overviews, INP, entity-led results, and GA4 vocabulary.

How to use this glossary for faster learning and better decisions

Start with the short definition, then read the one-line example to cement the meaning. Most entries are tuned for featured snippets and quick recall.

1. Use the scannable structure: skim H2/H3, then jump to the exact term.
2. Read the 40–60 word definition, then the one-line example.
3. Check “X vs Y” pairs to avoid costly implementation mistakes.
4. Verify thresholds and rules with the source links provided.
5. Bookmark the A–Z appendix for quick team alignment on SEO terms and definitions.

Core concepts every team should align on

Search works in stages, and many SEO terms map to these phases. Aligning on definitions prevents miscommunication between content, dev, and leadership. Keep in mind Google’s evolving landscape: new SERP features, Core Web Vitals updates, and privacy-driven analytics changes shift the language.

Crawling, indexing, and ranking—what each phase means in practice

Crawling is how search engines discover URLs; indexing is storing and understanding content; ranking is ordering results for a query. For example, your XML sitemap helps discovery (crawl), a canonical clarifies the preferred URL (index), and quality signals help the page win positions (rank). Think flow: discover → render → index → retrieve and rank.

On-page vs technical vs off-page SEO

On-page SEO shapes what’s on the page: titles, headings, copy, internal links, and structured data. Technical SEO ensures access and performance: status codes, canonical tags, robots directives, and Core Web Vitals. Off-page SEO builds reputation: links, mentions, and reviews. Most wins combine all three—use content + internal links + clean tech.

Ranking systems vs ranking signals

Ranking systems are the core algorithms Google uses to generate results (e.g., helpful content system), while ranking signals are inputs those systems consider (e.g., page speed, freshness). Understanding the distinction avoids over-weighting any single metric. See Google’s guide to ranking systems for context in the Sources.

Confusable pairs that cause costly mistakes

Some terms look similar but solve different problems. Use the quick decision rules below to pick the right control for your situation, and remember that many of these settings can combine—just avoid sending mixed signals.

robots.txt vs noindex

robots.txt controls crawling; it tells crawlers what not to fetch, but it doesn’t guarantee exclusion from indexing. noindex controls indexing; it allows crawling but instructs search engines not to index the page.

Rule of thumb: block crawl for resource waste (e.g., infinite calendars), use noindex for low-value pages you still need accessible.

Google limits robots.txt files to 500 KB (source: developers.google.com/search/docs/crawling-indexing/robots/intro).

canonical vs hreflang

Canonical consolidates duplicates or near-duplicates to a primary URL, guiding which version should be indexed and ranked. hreflang serves the correct language/region variant to users, typically across equivalent pages.

Use a self-referential canonical on each hreflang page, and ensure each language/region pair references each other to avoid conflicting signals. See Google’s hreflang guidance in Sources.

301 vs 302 redirects

301 indicates a permanent move; 302 indicates a temporary one. Modern search engines often pass most equity through either when usage is consistent, but 301s are better for consolidation and canonicalization. Use 302s for short-term campaigns or tests when you intend to restore the original URL.

1. Use 301 when URLs are retired, merged, or restructured long-term.
2. Use 302 for time-bound promos, A/B tests, or inventory outages.
3. Redirect at the server level; avoid chains and loops.
4. Keep destination content relevant and final.

rel="nofollow" vs "sponsored" vs "ugc"

Link attributes hint at link purpose and whether to pass reputation. Use nofollow when you can’t or don’t want to vouch for a link.

Use sponsored for paid placements. Use ugc for user-generated links like forum posts or comments. You can combine values as needed (e.g., rel="ugc nofollow") to reflect context accurately.

1. nofollow: Editorially unvetted links (example: open guestbook link).
2. sponsored: Ads, affiliates, paid placements (example: banner link).
3. ugc: Comment or forum links (example: community replies).

Acronyms decoded (with examples)

Acronyms are everywhere in SEO and analytics. Use these concise definitions to keep meetings crisp and dashboards clear. The examples show how each acronym appears in real reporting or planning.

E-E-A-T

E-E-A-T stands for Experience, Expertise, Authoritativeness, and Trust. It’s a qualitative framework in Google’s Search Quality Rater Guidelines, not a single ranking signal. Show first-hand experience, credible authorship, cited sources, and clear site trust signals (about pages, policies) to align with it.

Example: A medical article cites clinical studies and a licensed author bio.

CWV (LCP, CLS, INP)

Core Web Vitals are user-centric performance metrics. LCP (Largest Contentful Paint) measures loading speed; CLS (Cumulative Layout Shift) measures visual stability; INP (Interaction to Next Paint) measures overall responsiveness across a page’s interactions.

Interaction to Next Paint (INP) replaced FID as a Core Web Vital in 2024 (source: web.dev/inp/).

Example: Aim for LCP ≤2.5s, CLS ≤0.1, INP ≤200ms.

CTR, CVR, CPA, CPC

CTR is click-through rate (clicks/impressions), common in Search Console for organic queries. CVR is conversion rate (conversions/sessions). CPA is cost per acquisition and CPC is cost per click—primarily paid metrics in ad platforms.

Example: Organic CTR rises after title optimization; paid CPC falls after quality score improvements; sitewide CVR improves after checkout fixes.

Technical SEO terminology, explained with quick examples

Technical SEO ensures crawlers can access, render, understand, and index your pages efficiently. These terms anchor the work: control discovery, reduce duplication, and improve performance, all without blocking essential resources.

Robots.txt, crawl budget, and render-blocking resources

robots.txt directs crawler access to paths and resources; it’s about crawl control, not indexing. Crawl budget is how many URLs bots crawl on your site—important for large or frequently updated sites. Render-blocking resources (like unoptimized CSS/JS) delay content paint; avoid blocking critical CSS/JS needed for rendering.

Example: Allow CSS/JS rendering, disallow infinite parameter paths, and inline critical CSS where it helps.

Canonical tags, duplicate content, and parameter handling

Canonical tags (<link rel="canonical" href="https://example.com/preferred" />) signal the preferred URL when duplicates exist. Reinforce with consistent internal links, sitemaps, and redirects.

For URL parameters (sort, filter), avoid generating indexable duplicates; use self-referential canonicals on main versions and consider noindex on thin combinations. Avoid mixed signals like cross-canonicals and conflicting redirects.

Structured data and schema markup essentials

Structured data (often Schema.org vocabulary) helps search engines understand entities and relationships and can unlock eligibility for rich results. Mark up content types you actually have (e.g., Product, FAQ, Event) and keep data accurate and visible.

Eligibility isn’t guaranteed; it simply makes you eligible. Check the right types at schema.org and validate before shipping.

JavaScript SEO: CSR, SSR, hydration, and dynamic rendering

CSR (client-side rendering) builds HTML in the browser, which may delay indexing if critical content requires JS execution. SSR (server-side rendering) returns HTML upfront, improving crawlability.

Hydration attaches interactivity to SSR’d HTML. Dynamic rendering serves pre-rendered HTML to bots and JS to users; treat it as a workaround and keep parity to avoid cloaking-like mismatches.

SERP features and search experience terms you should know

Modern SERPs mix ten blue links with features that summarize, expand, or visually enhance results. Knowing what each feature is—and how eligibility works—guides your content and markup decisions.

Featured snippets, People Also Ask, and rich results

Featured snippets are extracted answers that appear above regular results. People Also Ask expands with related Q&As you can tap to reveal.

Rich results are enhanced listings (stars, FAQs, products) triggered by valid structured data. Clear, concise answers can earn snippets/PAA; structured data influences rich results eligibility, not snippets.

Knowledge Panels, sitelinks, and brand SERPs

Knowledge Panels are entity-driven summaries that appear for well-known brands, people, or places. Sitelinks are navigational shortcuts under a main result, usually driven by strong internal architecture and user behavior. Together, they shape brand SERPs—the first impression of your brand in search. Use clear site structure, Organization markup, and consistent naming to reinforce entity signals.

AI Overviews and how they differ from snippets

AI Overviews are generative summaries that synthesize information across sources to answer complex queries. They differ from featured snippets, which extract a direct passage from one page.

You can’t “mark up” for AI Overviews; focus on helpful, accurate content and strong E-E-A-T. Google provides help content on AI Overviews (source: support.google.com/websearch/answer/14507537).

Local SEO terminology that impacts visibility

Local visibility hinges on accurate business data, proximity, and reputation. These terms define the playing field for service-area businesses and brick-and-mortar locations.

Google Business Profile, NAP consistency, and citations

Google Business Profile (GBP) is your primary local listing. NAP is Name, Address, Phone; consistency across your site and directories reduces confusion and builds trust. Citations are mentions of your NAP on third-party sites.

Example: Match your GBP name and hours to your website footer and top directories to improve discovery and reduce user friction.

Relevance, distance, and prominence

Local ranking depends on relevance (how well a listing matches a query), distance (how far the user is from the business), and prominence (authority/reputation). Google cites relevance, distance, and prominence as key local ranking factors (source: support.google.com/business/answer/7091). Improve relevance with detailed categories/services, manage distance with accurate address/service area, and build prominence with reviews and links.

Measurement and analytics terms (GA4 and Search Console in context)

Aligning GA4 and Search Console definitions prevents apples-to-oranges reporting. Search Console reports how you appear on Google; GA4 reports what users do on your site. They answer different questions and won’t match exactly.

Impressions, clicks, CTR, and position (Search Console)

An impression occurs when your URL appears in a search result, even if the user doesn’t scroll to it. Clicks are visits from those results. CTR is clicks divided by impressions.

Average position is the mean top position your URL held for the queries shown. Don’t compare SC clicks to GA4 sessions directly; attribution windows and filters differ.

Sessions, engaged sessions, and conversions (GA4)

A session is a group of interactions within a time frame, started by the first event. Engaged sessions last 10+ seconds, have 2+ pageviews, or include a conversion. Conversions are key events you designate (e.g., purchase, lead).

Expect different totals from Search Console because GA4 measures onsite behavior, not SERP exposure.

Attribution models and assisted conversions

Attribution models assign credit across touchpoints. Data-driven models use your data to distribute credit; last click credits the final interaction. Assisted conversions capture non-final interactions that helped drive the outcome. In SEO reporting, use model comparison to show organic’s assist role across the journey, not just last-click wins.

The A–Z quick index of SEO terms (appendix)

Use this alphabetized micro-index to align teams fast. Each entry includes a snippet-friendly definition and a one-line example to anchor how the term shows up in work.

1. Anchor text: The clickable text of a link that gives context about the destination page. Descriptive, relevant anchors can help search engines understand topical relationships. Avoid stuffing keywords unnaturally. Example: Use “pricing plans” instead of “click here” to link to your pricing page.
2. Bounce rate: The percentage of sessions with no second pageview or qualifying interaction. In GA4, focus instead on “engagement rate,” the inverse of bounce. High bounce can indicate mismatch or fast answers. Example: A glossary page may have a high bounce but still satisfy intent.
3. Canonical tag: An HTML link element that signals the preferred URL when duplicates or variants exist. It consolidates indexing and reduces dilution. Reinforce with internal links and redirects for consistency. Example: Use a self-referential canonical on your primary product page.
4. Core Web Vitals: User-centered performance metrics (LCP, CLS, INP) that quantify loading, stability, and responsiveness. They affect real-user experience and can influence visibility. Improve via image optimization, critical CSS, and script deferral. Example: Compress hero images to improve LCP.
5. Crawl budget: The number of URLs a search engine will crawl on your site within a time period, influenced by site health and popularity. Matters most for large or frequently updated sites. Example: Prune faceted duplicates to free budget for fresh content.
6. Disavow file: A list you submit to tell Google to ignore certain backlinks when assessing your site. Use sparingly for clear, manipulative links you can’t remove. Example: Upload a disavow for spammy, automated forum profiles you don’t control.
7. Entity: A distinct, real-world thing (person, place, brand, concept) identified across sources. Entity understanding powers Knowledge Panels and semantic search. Clarify with consistent naming, schema, and authoritative mentions. Example: Use Organization schema and consistent brand naming for your company.
8. Featured snippet: A highlighted answer at the top of search results extracted from a page. You can earn it by providing concise, structured answers to common questions. Example: Start a section with a 40–60 word definition to target a snippet.
9. hreflang: An annotation that tells search engines which language/region version of a page to serve. Use bi-directional pairs and self-referential canonicals to avoid conflicts. Example: Link en-us and en-gb versions with reciprocal hreflang tags.
10. Indexing: The process of storing and understanding content so it can be retrieved for queries. Not all crawled pages are indexed. Improve with quality content, clear canonicals, and error-free rendering. Example: Fix blocked JS that prevents core content from rendering.
11. Indexing API: A programmatic way (limited to specific content types like job postings/live videos) to notify Google of updates. Not a general-purpose indexing tool. Example: Use Indexing API for job postings, not for typical blog updates.
12. JavaScript rendering: Executing JS to build the DOM used for indexing. If critical content requires JS, indexing can be delayed. Prefer SSR or hydration for primary content. Example: Render key product details in HTML to avoid discovery delays.
13. Knowledge Panel: An entity-driven summary box on the right rail or top of results. It draws from the Knowledge Graph and trusted sources. Reinforce with consistent information and schema. Example: Claim your brand’s panel and correct details where possible.
14. LCP (Largest Contentful Paint): Measures loading performance by timing when the largest content element becomes visible. Aim for ≤2.5s for a “good” experience. Improve with optimized images and server response. Example: Serve next-gen images and cache HTML.
15. Meta description: A short summary of a page shown in SERPs at Google’s discretion. It doesn’t directly rank but can influence CTR. Write compelling, accurate summaries. Example: Include the primary benefit and a call to action in ~150–160 characters.
16. NAP: Name, Address, Phone—core business identity for local SEO. Keep it consistent across your site and citations to avoid confusion. Example: Match your GBP name and hours to your site footer.
17. Open Graph: Metadata for social platforms that defines titles, images, and descriptions when links are shared. While not a ranking factor, it improves social click-through. Example: Set og:image to a 1200×630 image for crisp shares.
18. Page experience: A collection of signals (including Core Web Vitals and mobile-friendliness) reflecting user experience quality. It supports, but doesn’t replace, great content. Example: Fix intrusive interstitials that frustrate mobile users.
19. Query intent: The underlying goal behind a search (informational, navigational, transactional). Match content format and depth to the dominant intent. Example: Use a how-to with steps for “fix leaky faucet,” not a sales page.
20. Render-blocking: Resources (often CSS/JS) that delay first paint and content visibility. Inline critical CSS, defer non-critical JS, and preconnect to origins to speed up. Example: Move analytics script to load after main content.
21. Schema.org: A shared vocabulary for structured data used by search engines. Choose types that accurately describe your content and validate implementations. Example: Add Product and Offer markup to eligible product pages.
22. Sitemap: A file that lists URLs to help search engines discover content. XML sitemaps don’t guarantee indexing but support discovery and error detection. Example: Include only canonical, status-200 URLs you want indexed.
23. Title tag: The HTML element that names the page; it’s often shown as the SERP headline. Keep it descriptive, concise, and unique. Example: “Blue Running Shoes | Lightweight Men’s Trainers.”
24. UGC: User-generated content like comments, forum posts, and reviews. Mark links as rel="ugc" and moderate for quality. Example: Approve thoughtful reviews; block spammy link drops.
25. Vary header: A response header that indicates how content varies (e.g., by Accept-Language). It helps caches and crawlers fetch the right variant. Example: Use Vary: Accept-Language for localized content.
26. Web crawling: Automated fetching of URLs by bots to discover and refresh content. Support it with sitemaps, internal links, and stable architecture. Example: Link new collections from the main nav to invite faster crawling.

This appendix is a living index—revisit as your stack, SERPs, and analytics evolve.

Sources and further reading

1. Google robots.txt (https://developers.google.com/search/docs/crawling-indexing/robots/intro)
2. Google hreflang (https://developers.google.com/search/docs/specialty/international/localized-versions)
3. web.dev INP/CWV (https://web.dev/inp/)
4. Google AI Overviews help (https://support.google.com/websearch/answer/14507537)
5. Google Local ranking (https://support.google.com/business/answer/7091)
6. Google ranking systems (https://developers.google.com/search/docs/appearance/ranking-systems)
7. RFC 9309 Robots Exclusion Protocol (https://www.rfc-editor.org/rfc/rfc9309)
8. schema.org (https://schema.org/)

FAQs about SEO terminology

1. When should I use robots.txt instead of noindex for pages I don’t want in Google? Use robots.txt to prevent crawling of infinite or low-value paths that waste resources. Use noindex when the page should be accessible but excluded from the index.
2. What’s the practical difference between canonical tags and hreflang for international sites? Canonical consolidates duplicates to one preferred URL; hreflang serves language/region variants. Use self-referential canonicals on each hreflang page plus reciprocal hreflang links.
3. How does INP change Core Web Vitals compared to FID, and what’s a good INP threshold? INP measures overall interaction latency across the page, replacing FID. Aim for ≤200 ms for a “good” experience (see web.dev/inp/).
4. Which redirect is best for temporary campaigns: 301 or 302, and why? Use 302 for temporary campaigns you’ll revert; it signals a short-term change. Use 301 for permanent moves to consolidate equity.
5. How do Search Console “impressions” differ from GA4 “sessions”? Impressions are SERP exposures; sessions are onsite visits. They measure different things and won’t match; use each for its purpose.
6. What is crawl budget and when does it actually matter? It’s how much crawling your site gets. It matters for large or frequently updated sites; small sites rarely hit limits if they’re healthy.
7. How do CSR, SSR, and hydration affect crawling and rendering of JavaScript-heavy sites? CSR may delay indexing if content needs JS; SSR returns HTML upfront; hydration adds interactivity post-SSR. Prefer SSR/hydration for primary content.
8. How should I handle URL parameters to avoid duplicate content issues? Use self-referential canonicals on primary versions, avoid indexable thin combinations, and keep internal links pointing to canonical URLs. If needed, add noindex to low-value parameter pages.