AI Search Reference
AI SEO Glossary
Every term you need to understand GEO, AEO, LLM optimisation, and AI-powered search. 25 definitions in plain language.
AEO (Answer Engine Optimization)
AEO is the practice of optimising content to appear as the direct answer when users query AI-powered answer engines such as ChatGPT, Perplexity, or Google AI Overviews. Unlike traditional SEO, which targets ranked blue links, AEO targets the synthesised response itself. Brands that succeed at AEO are cited verbatim or paraphrased in AI answers without requiring the user to click through.
AI Overview
AI Overview is Google's AI-generated summary displayed at the top of search results, powered by Gemini. It synthesises information from multiple web sources and presents a direct answer before any organic results. Being featured in AI Overviews requires strong E-E-A-T signals, structured data, and clear, citable prose.
AI Referral Traffic
AI referral traffic is website visits that originate from links within AI platform responses. When ChatGPT, Perplexity, or Gemini cites a source and a user clicks through, that session appears in analytics as AI referral traffic. It is a lagging indicator of AI visibility and a growing share of premium inbound traffic.
AI Visibility
AI visibility measures how consistently a brand, product, or service appears in AI-generated answers across ChatGPT, Perplexity, Gemini, Claude, and Microsoft Copilot. A brand with high AI visibility is mentioned, cited, or recommended across a broad set of relevant conversational queries. It is the AI-era equivalent of organic search visibility.
Brand Entity
A brand entity is a brand's distinct digital identity as understood and stored by AI systems, knowledge graphs, and structured databases. A well-defined brand entity has consistent name, description, attributes, and relationships that LLMs can confidently surface. Building a strong brand entity is foundational to AI visibility.
Citation Building
Citation building is the process of earning mentions and references to your brand across authoritative online sources — publications, directories, review platforms, and high-authority blogs — that LLMs index during training and retrieval. The more consistently your brand is cited across trusted sources, the more likely it is to appear in AI responses.
Citation Rate
Citation rate is the frequency with which your brand is cited in AI platform responses across a tracked set of relevant prompts. It is typically expressed as a percentage: the proportion of tested prompts where your brand appears at least once. Citation rate is a core KPI in any AI visibility programme.
Conversational Query
A conversational query is a natural language question phrased the way a person would ask an AI assistant — full sentences, context-rich, and intent-clear. Examples include 'What is the best LLM optimisation agency in Europe?' versus a keyword like 'LLM agency'. Content optimised for conversational queries is more likely to be cited in AI answers.
Digital PR for GEO
Digital PR for GEO is the practice of earning brand mentions on authoritative, high-domain-authority websites with the explicit goal of increasing AI citation likelihood. LLMs favour brands that appear in credible, well-linked publications. Digital PR campaigns designed around GEO target outlets that AI systems are most likely to have indexed and weighted.
E-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness, and Trustworthiness — quality signals used by Google's search quality raters and increasingly reflected in what LLMs learn to trust. Content demonstrating first-hand experience, clear author credentials, citations from authoritative sources, and factual accuracy scores higher on E-E-A-T and is more likely to be cited by AI systems.
FAQPage Schema
FAQPage schema is structured data markup (using Schema.org vocabulary) that wraps question-and-answer pairs on a page. It significantly increases the likelihood that your content is surfaced in Google AI Overviews and other AI answer engines because it provides machine-readable signals about what questions your page answers and exactly how.
GEO (Generative Engine Optimization)
GEO is the practice of optimising content, brand presence, and digital signals so that AI-powered search engines — ChatGPT, Perplexity, Google AI Overviews, Gemini, and Microsoft Copilot — cite and recommend your brand. GEO encompasses technical optimisation, content strategy, entity building, and citation acquisition. It is the successor discipline to traditional SEO.
Knowledge Graph
A knowledge graph is a structured database of entities (people, brands, products, places) and the semantic relationships between them. Google's Knowledge Graph, Wikidata, and similar systems are used by both search engines and LLMs to understand who and what entities are. Brands with strong knowledge graph presence are significantly more likely to be surfaced by AI systems.
LLM Optimisation
LLM optimisation is the practice of making your content understandable, trustworthy, and retrievable by large language models. It covers everything from clear, factual prose to structured data markup, authoritative citation building, and technical accessibility (such as maintaining a clean llms.txt file). LLM optimisation is the technical layer beneath GEO strategy.
LLMs.txt
LLMs.txt is a plain-text file placed at the root of your website (e.g. akravo.com/llms.txt) that tells AI crawlers what your site is about, who runs it, what services are offered, and which pages are most important. Modelled on robots.txt, it is an emerging standard for communicating directly with AI systems at crawl time.
Multimodal Content
Multimodal content combines text, images, video, and audio in a way that AI systems can parse and understand across modalities. As AI search engines become increasingly multimodal (able to process images and video alongside text), brands that produce well-structured, captioned, and semantically tagged media gain broader AI visibility.
Prompt Coverage
Prompt coverage is the percentage of your tracked target prompts where your brand appears across AI platforms. If you track 100 prompts relevant to your market and appear in 40 of them, your prompt coverage is 40%. Growing prompt coverage is the primary goal of an AI visibility programme.
Prompt Research
Prompt research is the systematic process of mapping the natural language questions and queries that your target buyers ask AI platforms at every stage of the buying journey. It is the AI-era equivalent of keyword research. Prompt research reveals which prompts your brand already appears in and which represent citation gaps to close.
RAG (Retrieval Augmented Generation)
RAG is an AI architecture in which a language model retrieves relevant external documents at inference time and uses them to supplement or ground its response. Perplexity and Google AI Overviews are built on RAG-style systems. Brands that publish clear, well-structured, authoritative content are more likely to be retrieved and cited in RAG-based AI responses.
Semantic SEO
Semantic SEO is the practice of optimising content for meaning and conceptual relationships rather than exact keyword matching. It involves building comprehensive topical coverage, using related terms and entities, and structuring content so that both search engines and LLMs understand the full context of what is being discussed.
Speakable Schema
Speakable schema is a Schema.org markup type that identifies specific passages on a page as the most citable, quotable, and summarisable sections. It signals to AI systems and voice assistants exactly which content is worth extracting and repeating. Pages with Speakable markup are better positioned for direct citation in AI answers.
Zero-click Search
Zero-click search occurs when a user receives a complete answer directly in the search results or AI response without clicking through to any website. The rise of AI Overviews and conversational AI has dramatically increased zero-click rates. GEO strategy must account for zero-click — the goal shifts from driving clicks to ensuring your brand is the cited source.
Frequently Asked Questions
What is the difference between GEO and SEO?
Traditional SEO optimises for ranking in blue-link search results. GEO (Generative Engine Optimization) optimises for being cited and recommended by AI-powered search engines like ChatGPT, Perplexity, and Google AI Overviews. GEO focuses on entity authority, citation building, and conversational content rather than keyword density and backlink volume.
What does Share of Model mean?
Share of Model (SoM) is the percentage of relevant AI prompts where your brand is mentioned in the AI response. If you track 100 prompts relevant to your market and your brand appears in 35 of them, your Share of Model is 35%. It is the AI-era equivalent of share of voice.
What is Citation Rate in AI search?
Citation rate is the frequency with which your brand appears in AI-generated answers across a tracked set of prompts. It is expressed as a percentage — the proportion of tested queries where the AI mentions or cites your brand at least once. Improving citation rate is the core goal of an AI visibility programme.
How is LLM Optimisation different from AEO?
AEO (Answer Engine Optimization) is a strategy — it defines the goal of appearing in AI answers. LLM Optimisation is the technical execution layer — the specific practices (structured data, entity building, clear prose, llms.txt, speakable schema) used to make your content understandable and trustworthy to large language models. AEO is the 'what'; LLM optimisation is the 'how'.
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