SEO & GEO Glossary
Plain-English definitions of the SEO and AI-search terms that actually matter — written by people who have watched a site lose 89% of its traffic and learned exactly why. No hype, no keyword stuffing, no promises we can't keep.
AI Search
AEO (Answer Engine Optimization)
Structuring content so answer engines can lift a direct answer from it — for featured snippets, voice results and AI answers.
AI Overviews
Google's AI-generated summary at the top of some results. You can be cited but not paid for placement, and only if you're indexed.
AIO (AI Optimization / AI Overviews)
A catch-all acronym for optimizing toward AI answers — sometimes 'AI Optimization', sometimes shorthand for Google's AI Overviews specifically.
GEO (Generative Engine Optimization)
Improving how often generative AI answers (ChatGPT, Perplexity, Gemini) cite your site. Visibility is measured, not bought.
llms.txt
A proposed root file curating a site's key content for AI systems. Adoption is limited; it does not replace being indexed.
Content
Keyword Cannibalization
When several pages on one site target the same query and compete with each other, splitting signals and confusing engines.
Thin Content
Pages with little unique value — auto-generated, scraped, doorway or near-duplicate pages that spam systems demote.
Fundamentals
Indexing
Storing a crawled page in a search engine's index so it can appear in results. Crawled is not the same as indexed.
PPC (Pay-Per-Click)
An advertising model where you pay only when someone clicks your ad — the pricing mechanism behind search and social ad auctions.
SEM (Search Engine Marketing)
The umbrella for getting visibility on search engines — historically both paid ads and organic SEO, though today it usually means the paid side.
SEO (Search Engine Optimization)
The practice of earning more relevant traffic from search engines by making a site easier to crawl, index, understand and trust.
Google Systems
Core Update
A broad, periodic change to Google's ranking systems. Rankings shift site-wide; recovery comes from improving overall quality.
E-E-A-T (Experience, Expertise, Authoritativeness, Trust)
Google's quality framework: content should show real experience, expertise, authority and trust. Not a score, but a lens.
SpamBrain
Google's AI-based spam-detection system. It demotes scaled, near-duplicate, low-value content — often site-wide, with no manual action.
On-Page
Meta Description
A page's summary tag. Not a ranking factor, but it often becomes the search snippet, so it drives click-through.
Title Tag
A page's <title>, shown as the clickable result headline. One of the strongest on-page relevance signals — keep it unique.
Technical SEO
301 vs 302 vs 410
Status codes for moved or removed pages: 301 permanent redirect, 302 temporary redirect, 410 gone. Each signals a different intent.
Canonical Tag
A rel="canonical" link that names the preferred URL for a page, telling search engines which version to index when duplicates exist.
Crawl Budget
The finite attention search engines spend crawling a site. Matters mainly for large sites; wasted on junk URLs, it starves real pages.
Hreflang
Link annotations that tell search engines which language and region each version of a page targets, so the right one is served.
Noindex
A directive that tells search engines to keep a page out of their index. The page must stay crawlable for the tag to be seen.
Structured Data (Schema Markup)
Machine-readable markup (usually JSON-LD) that labels page content so engines can understand it and show rich results.
XML Sitemap
A machine-readable list of the canonical, indexable URLs on a site, submitted to search engines to aid discovery.
robots.txt
A file at the site root that tells crawlers which paths they may or may not fetch. It controls crawling, not indexing.