The SEO, AEO & GEO glossary.
Thirty-seven terms that decide whether machines understand your business - defined without jargon, including three we coined ourselves. Free to cite with attribution.
SEO
Search Engine Optimization - the practice of making a website findable, understandable and rankable by search engines like Google and Bing.
AEO
Answer Engine Optimization - structuring content so answer engines (featured snippets, AI Overviews, voice assistants) can extract and present it as a direct answer.
GEO
Generative Engine Optimization - making a brand readable, trustworthy and citable by generative AI systems such as ChatGPT, Claude, Gemini and Perplexity.
LLM
Large Language Model - the AI technology behind ChatGPT, Claude and Gemini; trained on text to generate answers, including answers about your brand.
llms.txt
A plain-text file at a site's root describing the site for AI systems - a housekeeping signal of AI-era readiness. Not used by Google for ranking.
AI crawler
An automated bot from an AI company (GPTBot, ClaudeBot, PerplexityBot) that reads websites for training data or live answers. Controlled via robots.txt.
robots.txt
The file that tells crawlers - search and AI - what they may read. In the AI era it is a policy document, not a formality.
Schema markup
Machine-readable code (JSON-LD) describing what a page is about - business, product, FAQ - so machines read facts instead of guessing.
JSON-LD
The format Google recommends for schema markup: a small script of structured facts embedded in a page.
FAQPage schema
Schema marking up questions and answers - the most answer-engine-relevant markup, provided the questions are visible on the page.
AI Overviews
Google's AI-generated summaries at the top of results, assembled from sources it deems reliable - being one of those sources is the new ranking.
Citation (AI)
When an AI assistant names or links a source in its answer. The AI-era equivalent of ranking #1.
Citation Gravitas - coined here
The accumulated weight a brand carries inside AI-generated answers - how often and how confidently systems cite it. Coined by SynapseIN, 2026.
Ghost Query - coined here
A question your customers ask AI assistants where your brand should appear but does not - invisible lost demand. Coined by SynapseIN, 2026.
Entity Friction - coined here
The resistance machines meet when working out who a brand is - inconsistent names and data that lower citation likelihood. Coined by SynapseIN, 2026.
Entity
A distinct thing search engines recognize - a brand, person or place - connected in a knowledge graph. Consistent entity data is AI-visibility groundwork.
E-E-A-T
Experience, Expertise, Authoritativeness, Trustworthiness - Google's framework for judging content quality, especially in health and finance.
Core Web Vitals
Google's speed and stability metrics for real user experience - loading, interactivity, layout shift.
Crawl budget
How many pages a search engine will fetch from your site per visit - wasted on junk pages if a site is bloated.
Indexation
Whether a page is stored in a search engine's database and eligible to appear in results. Crawled does not mean indexed.
Canonical URL
The address you declare as the official version of a page, preventing duplicate-content confusion.
Structured data
The umbrella term for machine-readable page information - schema markup is its main form.
Zero-click search
A search resolved on the results page itself - snippet, AI answer - without a website visit. Brands win by being the cited source.
IndexNow
A protocol for instantly notifying Bing, Yandex and others about new or changed pages, instead of waiting for a crawl.
Knowledge graph
A search engine's map of entities and relationships - the reason Google shows fact panels, and where your brand identity lives.
Answer block
A short, direct answer placed near the top of a page, structured for machines to lift - a core AEO technique.
LLMO - added July 2026
Large Language Model Optimization - another industry name for the discipline SynapseIN calls GEO: making a brand readable, trustworthy and citable by AI language models.
AIO - added July 2026
AI Optimization - umbrella acronym some agencies use for optimizing visibility across AI search surfaces. Substantially the same discipline as GEO/LLMO.
AI SEO - added July 2026
The everyday phrase for adapting search optimization to AI-driven results - AI Overviews, chat assistants and answer engines. Covers the combined SEO + AEO + GEO stack.
Conversational search - added July 2026
Searching by asking questions in natural language - to chatbots, voice assistants or AI-powered search. Rewards content that answers questions directly instead of targeting keywords.
SearchGPT / ChatGPT Search - added July 2026
OpenAI's web-connected search experience inside ChatGPT. It reads live websites via OAI-SearchBot - crawlable, fast, well-structured sites can be quoted in its answers.
RAG - added July 2026
Retrieval-Augmented Generation - the technique AI assistants use to fetch fresh web content before answering. The reason a well-structured page can be cited within days, not after months of model training.
Agentic commerce - added July 2026
The emerging pattern of AI agents researching, shortlisting and transacting on a customer's behalf. The next visibility question: can an AI agent read, trust and act on your website?
AI agent - added July 2026
Software that performs multi-step tasks autonomously - browsing sites, comparing options, filling forms. Google's Agentic Browsing checks already grade sites on agent-friendliness.
Brand mention - added July 2026
Any naming of your brand on a third-party site, linked or not. AI systems treat consistent mentions across trusted sources as evidence of legitimacy - the raw material of citations.
Digital PR - added July 2026
Earning coverage and mentions in press, podcasts and trade publications. In the AI era it doubles as GEO fuel: third-party corroboration is what makes machines confident enough to cite you.
SXO - added July 2026
Search Experience Optimization - the view that ranking, user experience and conversion are one discipline: being found is worthless if the page that greets the visitor is slow, confusing or untrustworthy. We practice this as SEO-first web development.
Term missing?
Tell us and we will define it honestly - hello@synapsein.com. And if the vocabulary is new to you, the plain-English guide connects it all.