The terminology can be confusing. AEO, GEO, AI SEO, RAG, LLMs, entities, semantic search, citations, AI Overviews, query fan-out, and AI visibility all describe different parts of a rapidly evolving search ecosystem.
This AI SEO glossary explains the most important terms in plain English.
A
AEO (Answer Engine Optimization)
Optimizing content and websites so answer-oriented search systems can understand and use their information when responding to user questions. AEO commonly involves search intent, question answering, content structure, entities, concise answers, and information architecture.
AI SEO
The broader practice of optimizing websites, content, entities, and digital presence for search experiences involving artificial intelligence. Includes traditional SEO, AEO, GEO, Semantic SEO, Entity SEO, AI search, retrieval, citations, AI visibility, and technical SEO.
AI Search
Search experiences that use artificial intelligence to understand queries, retrieve information, synthesize information, or generate answers (e.g. Google AI Overviews, ChatGPT search, Gemini, Perplexity).
AI Overviews
Google's AI-generated responses that appear within Google Search for certain queries, synthesizing information and providing links to supporting webpages.
AI Mode
Google's more conversational, AI-powered search experience designed for complex and exploratory queries. It can break questions into multiple searches and synthesize information from different sources.
AI Citation
A reference or link to a source included in an AI-generated response, providing evidence or supporting information for claims made in an answer.
AI Crawler
An automated system that requests webpages or online resources for purposes associated with AI systems (e.g., Googlebot, GPTBot, PerplexityBot). A crawler request does not necessarily mean a page will later appear in an AI answer.
AI-Generated Content
Content created substantially with the assistance of artificial intelligence. Useful, original, accurate, and relevant content is evaluated on quality regardless of generation method.
AI Search Visibility
Describes how often and where a brand, website, entity, product, or piece of content appears in AI-powered search experiences across mentions, citations, links, and recommendations.
AI Traffic
Traffic arriving at a website from an AI-powered platform or AI search experience, including referral traffic from AI assistants and generative search interfaces.
Answer Engine
A system designed to provide direct answers to user questions rather than simply returning a list of webpages.
Attribution
How traffic, conversions, mentions, citations, or outcomes are assigned to an AI search interaction.
B
Brand Entity
The identifiable entity representing a company, organization, product brand, or commercial identity in search systems and knowledge graphs.
Brand Mention
A reference to a brand in content or an AI-generated response without necessarily including a hyperlink.
Backlink
A hyperlink from another website to your website. Backlinks contribute to domain authority and discovery across search ecosystems.
C
Citation
A reference to a source used to support information in generative search responses.
Citation Rate
Measurement of how frequently a website or brand is cited across a defined set of AI search queries (e.g., 30 citations across 100 monitored responses = 30% citation rate).
Citation Tracking
Monitoring when and where a website, page, or brand appears as a cited source in AI-generated answers.
Chunk / Chunking
A segment of content that can be processed or retrieved as part of an information-retrieval system (commonly used in RAG systems).
Content Retrieval
Finding relevant content from a search index, database, vector store, or information source.
Conversational Search
Search conducted using natural, conversational language rather than short keyword phrases.
D
Digital PR
Using online publications, news, industry websites, research, and campaigns to build external awareness, mentions, and authority for AI search ecosystems.
Document Retrieval
Retrieving relevant documents from an index in response to a user query.
E
Entity
A distinct, identifiable person, organization, place, product, concept, or thing (e.g., Google, ChatGPT, India, Shopify, Elon Musk, SEO).
Entity SEO
Focuses on helping search systems understand entities, their attributes, and their relationships beyond exact keyword matching.
Entity Mapping
Identifying important entities within a topic and documenting their relationships (e.g., Company → produces → Product).
Entity Relationship
Describes how two entities are connected (e.g., Google → operates → Search).
Entity Disambiguation
Determining which specific entity is being discussed when multiple entities share similar names.
F
Featured Snippet
A highlighted organic search result displayed at the top of Google SERPs to answer a query directly. Distinct from AI Overviews.
Freshness
How current information is. Critical for topics where facts and real-time events change rapidly.
G
Generative AI
AI systems capable of generating new content (text, images, code) from user prompts.
Generative Engine
A system that generates responses by synthesizing information rather than presenting a conventional ranked list of blue links.
Generative Engine Optimization (GEO)
Strategies intended to improve visibility within generative search experiences (retrieval, entities, citations, brand mentions, evidence).
Generative Search
Combines traditional search retrieval with generative AI to produce synthesized responses to user queries.
Google AI Overviews
Google's generative search feature providing synthesized answers with supporting web citations.
H
Hallucination
Generated AI information that is inaccurate, unsupported, or fabricated. Grounding and factual evidence mitigate hallucinations.
Head Query
A broad search query with high search volume (e.g. "SEO"). Contrast with long-tail queries.
I
Information Gain
The unique value added when content provides useful, non-redundant information beyond what is already available elsewhere (original research, new data, proprietary insights).
Information Retrieval (IR)
The computer science discipline of finding relevant information from a database or search index in response to a query.
Intent (Search Intent)
What the user is trying to accomplish with a query (Informational, Navigational, Commercial, Transactional).
Index / Indexability
A search index is a structured database of web pages. Indexability refers to whether a page can be stored and retrieved by search engines.
K
Knowledge Graph
A structured graph database representing entities and their interconnected relationships.
Keyword / Keyword Clustering
Keywords are search terms. Keyword clustering groups queries with similar intent into comprehensive content topics.
L
LLM (Large Language Model)
Machine-learning neural networks trained on vast text corpora to process, understand, and generate natural language.
LLM Traffic
Website visits originating from LLM platforms or AI search tools.
LLM Optimization
Improving the likelihood that information about a brand or topic is understood and surfaced by LLM systems.
llms.txt
A proposed Markdown convention intended to provide AI tools with a curated site summary map. Google officially does NOT use llms.txt for Google Search or AI Overviews. Read our full study: llms.txt for Google AI SEO.
Long-Tail Query
A specific, multi-word search query expressing precise intent (e.g. "best technical SEO tools for SaaS").
M
Machine-Readable Content
Content structured so software can easily process it (HTML5, JSON-LD Schema, XML).
Mention
A textual reference to an entity, brand, or product across the web.
Multimodal Search
Search accepting multiple input types (text, images, voice, video).
N
Natural Language Query
Queries formulated in normal human conversational speech rather than concise keyword fragments.
N-gram
A contiguous sequence of n items from a given sample of text used in linguistic and search analysis.
O
Organic Search
Unpaid search results returned by search engines based on relevance and authority.
Original Research
Primary data, benchmarks, experiments, or surveys published by a brand that others cite.
P
Passage / Passage Retrieval
Identifying and extracting specific relevant text passages within long documents to answer queries.
Perplexity
An AI answer engine combining real-time web search retrieval with LLM synthesis and citations.
Prompt
Text input or instructions provided to an AI system.
Q
Query
The user's text or voice input to a search engine or AI system.
Query Expansion
Modifying or adding terms to a user's query to improve retrieval coverage.
Query Fan-Out
Breaking a complex user question into multiple parallel sub-queries to gather multi-source context before generating an answer.
R
RAG (Retrieval-Augmented Generation)
Architecture where an LLM retrieves external documents from a search index or vector database before generating an answer: Query → Retrieval → Context → Generation.
Retrieval
Finding relevant information from an index or database in response to a query.
Retrieval Optimization
Formatting content structure, entity clarity, and passage relevance to maximize retrieval match rates.
Robots.txt
Standard file providing crawler access directives to search engine user agents.
S
Semantic SEO
Optimizing content around meaning, concepts, entities, and context rather than exact keyword frequency.
Semantic Search
Search that understands the conceptual intent behind queries rather than relying solely on string matching.
Schema.org / Structured Data
Standardized JSON-LD vocabulary describing page entities to machines. Read our empirical findings: Schema & AI SEO Evidence Report.
Search Console
Google's webmaster tool for monitoring search performance, including the Generative AI performance report.
T
Topical Authority
The depth, breadth, and factual credibility of a site's overall coverage of a subject area.
Topic Cluster
Organizing content into a pillar page and interlinked subtopic pages to establish semantic authority.
Topical Coverage
How thoroughly a website addresses all subtopics, questions, and entity relationships within a niche.
U
UCP (Universal Commerce Protocol)
An emerging protocol facilitating commerce transactions directly across AI interfaces.
User Intent
See Search Intent.
V
Vector Database / Vector Search
Stores high-dimensional numerical embeddings of text to retrieve content based on mathematical concept similarity rather than keyword matching.
Visibility
How prominently a domain or entity appears across traditional SERPs and AI search answers.
W
Web Grounding
Connecting an LLM to live search index retrieval so generated responses are grounded in real-time web facts.
Web Mention
References to an entity across news, blogs, and external web publications.
X
XML Sitemap
A file listing important website URLs to help search engines discover and crawl pages efficiently.
Z
Zero-Click Search
Searches where users find their complete answer directly on the search page (or AI answer) without clicking an external website link.
The AI SEO Vocabulary Map
Frequently Asked Questions
What is the difference between AEO and GEO?
AEO emphasizes answer-oriented search and direct extraction, while GEO focuses on multi-source retrieval, AI citations, brand mentions, and generative responses across systems like ChatGPT, Gemini, and Perplexity.
What is RAG in AI SEO?
RAG (Retrieval-Augmented Generation) is the architecture where an AI search engine retrieves external web pages from an index to ground its LLM response in real-time web facts.
Are keywords still relevant in AI SEO?
Yes, but keywords are now evaluated alongside entities, search intent, semantic relationships, passage relevance, and information gain.
Final Takeaway
The vocabulary will continue to evolve. The durable skill isn't memorizing every new acronym—it's understanding the relationships between queries, intent, entities, semantics, retrieval, evidence, generation, citations, and visibility.
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