Glossary

SEO glossary

Plain definitions, updated for AI search in 2026.

AI Overviews: AI-generated summaries Google shows above some search results, with links to sources. Google reported 2.5 billion monthly users in 2026.
AI Mode: Google's conversational search mode that answers with AI and supporting links. Passed 1 billion monthly users by mid-2026.
Aggregator: A site that lists many businesses in one category, such as Practo, Yelp or Angi. Competes for broad searches and is also a listing channel.
Alt text: A short description of an image in HTML. Helps screen readers and image search.
Backlink: A link from another website to yours. Relevant, editorial links help search engines judge authority.
Backend search terms: Hidden keywords in an Amazon listing. Indexed in most marketplaces only when under 250 bytes.
Canonical URL: The version of a page you ask search engines to index when several URLs show similar content.
Citation: A mention of your business name, address and phone on another site, usually a directory.
Click-through rate (CTR): Clicks divided by impressions. Position 1 on Google gets 22.6% without an AI answer and 3.6% with one (2026).
Cluster: A group of keywords that one page can answer.
Core Web Vitals: Google's user-experience metrics: LCP (loading, good ≤ 2.5 s), INP (responsiveness, good ≤ 200 ms) and CLS (visual stability, good ≤ 0.1), measured at the 75th percentile of real users.
Cost per click (CPC): What advertisers pay per click in Google Ads. Used to value organic traffic.
Crawling: Search engines fetching pages. Controlled by robots.txt.
Doorway pages: Many near-identical pages made only to rank for location or keyword variations. Against Google's spam policies.
E-E-A-T: Experience, expertise, authoritativeness and trust: the qualities Google's raters look for. A framework, not a score.
Featured snippet: A highlighted answer box at the top of results, quoting one page. 11.4% CTR where shown (2026).
GEO (generative engine optimization): Work to be cited or recommended in AI answers. Mostly the same fundamentals as SEO plus clear, quotable facts.
Google Business Profile: Your free business listing on Google Search and Maps (formerly Google My Business).
Hreflang: Markup that tells search engines about language or regional versions of a page.
Indexing: Search engines storing a page so it can appear in results. Crawled doesn't mean indexed.
IndexNow: A protocol that tells Bing and other engines immediately when pages change.
Internal link: A link from one page on your site to another. Guides users and spreads relevance.

Keyword difficulty (KD): A tool's estimate of how hard it is to rank on page one. Each tool calculates it differently.
Local pack: The map and three businesses Google shows for local searches. Position 1 gets 14.8% CTR (2026).
Long-tail keyword: A longer, specific search with lower volume and usually easier competition.
Meta description: The page summary in HTML that search engines may show under the title.
NAP: Name, address and phone number. Should be consistent across your site and listings.
Noindex: A directive that keeps a page out of search results. The page must be crawlable for it to work.
Organic traffic: Visits from unpaid search results.
Programmatic SEO: Creating many pages from data. Useful only when each page has distinct value.
Quick win: A keyword group with good value and low difficulty that can rank within a few months.
Robots.txt: A file that tells crawlers which paths they may fetch. It controls crawling, not indexing.
Schema markup: Structured data (usually JSON-LD) describing a page's content. Can make pages eligible for rich results.
Search intent: What the searcher wants: local, transactional, commercial, informational or a specific brand.
Search volume: Average monthly searches for a keyword. Exact figures come from Google Ads data; most tools estimate.
SERP: Search engine results page.
Share of voice: Your share of clicks or visibility across a keyword set compared with competitors.
Sitemap: An XML file listing the URLs you want indexed.
Structured data: See schema markup.
Title tag: The page title in HTML, usually shown as the clickable headline in results.
Topical authority: How thoroughly and usefully a site covers a subject. Built with coherent content, not article quotas.
Traffic value: Organic clicks multiplied by CPC: what the same traffic would cost as ads.
UTM parameters: Tags added to links (utm_source, utm_medium, utm_campaign) to track where visits come from.
YMYL: "Your money or your life" topics such as health, finance and law, held to higher quality standards.
Zero-click search: A search that ends without a click, often because the answer appears on the results page.