AIO. GEO. AEO.
What do they actually mean?
The new vocabulary of AI Search is moving fast. This is the definitive reference — written by the team that helped define it.
AI Search
Artificial Intelligence-Powered Search
What it is
AI Search refers to any search experience where an artificial intelligence model — rather than a traditional algorithm — generates, synthesises, or curates the answer to a user's query. Instead of returning a ranked list of links, AI Search produces a direct, conversational response, often drawing from multiple sources and presenting a unified answer.
The platforms driving AI Search
- Perplexity AI — a standalone AI search engine that cites sources in real-time
- ChatGPT (Search mode) — OpenAI's GPT-4o with live web browsing
- Google AI Overviews (formerly SGE) — Google's generative answer layer at the top of search results
- Microsoft Copilot — Bing-integrated AI answers across Microsoft products
- Claude (Anthropic) — research-grade AI assistant increasingly used for query resolution
Why it changes everything
Traditional SEO assumes users will scan a list of results and click through to your site. AI Search eliminates that step. The AI reads your content on your behalf, synthesises it, and decides whether — and how — to credit you. If your brand is not legible to AI models, you are invisible regardless of your page ranking.
AIO
AI Influence Optimization — coined and defined by AI Search Lab
What it is
AIO (AI Influence Optimization) is the discipline of engineering your brand's content, structure, and authority signals specifically so that AI models select you as a trusted source when generating responses about your industry, product, or topic area.
It is distinct from SEO (which targets search engine ranking algorithms) and from GEO (which is a broader academic term). AIO is a practitioner methodology — built to be implemented, measured, and iterated.
The core AIO signals
- Entity recognition — Is your brand a well-defined entity that AI models can identify with confidence?
- Content authority — Do you publish the canonical reference content for your niche?
- Structured data — Is your Schema markup rich enough for AI parsers to understand your context?
- Citation distribution — Does your content appear in the sources AI models use for retrieval?
- Consistency across platforms — Is your brand represented consistently across the web entities AI models trust?
AIO vs. SEO — the key difference
SEO optimises for ranking. AIO optimises for citation. A page can rank #1 on Google and never be cited by ChatGPT. Conversely, a brand that AI models cite consistently may not even appear in the top 10 traditional search results. They are parallel disciplines with overlapping but distinct mechanics.
GEO
Generative Engine Optimization
What it is
GEO (Generative Engine Optimization) is an academic and industry term that describes the practice of optimising content to appear in generative AI responses. The term was popularised following academic research published in 2023–2024 that studied how content characteristics influenced citation rates in AI-generated answers.
How GEO works
- Source credibility signals — authoritative citations, expert authorship, institutional backing
- Content fluency — clear, well-structured writing that AI models can parse and summarise
- Query-response alignment — content that directly and completely answers the questions users are asking
- Freshness — regularly updated content that reflects current knowledge states
GEO vs. AIO — what's the difference?
GEO is a descriptive category term — it describes the general space of "optimising for generative engines." AIO is a specific, practitioner-level methodology with defined signals, measurement frameworks, and implementation playbooks. Think of GEO as the genre, AIO as the method.
Many agencies use GEO and AIO interchangeably. They are not identical — but the overlap is significant enough that both terms often refer to the same client work.
AEO
Answer Engine Optimization
What it is
AEO (Answer Engine Optimization) is the practice of structuring content to appear in direct answer boxes, featured snippets, voice search responses, and AI-generated summaries. It pre-dates the current AI Search wave — AEO strategies were developed for voice assistants (Siri, Alexa, Google Assistant) and Google's featured snippet system.
AEO techniques
- FAQ Schema markup — structured Q&A that search engines and AI models can directly parse
- Featured snippet optimisation — concise, definitive answers at the start of key content sections
- Speakable Schema — markup that identifies content suitable for voice assistant responses
- HowTo and Step Schema — structured procedural content for process queries
AEO in the age of AI Search
AEO techniques have become a foundational layer within both AIO and GEO strategy. The structured data practices developed for AEO — FAQ Schema, Speakable, HowTo — are the same signals that AI models use to parse and cite content. AEO is now a subset of a complete AI Search visibility strategy, not a standalone discipline.
LLMO
Large Language Model Optimization
What it is
LLMO (Large Language Model Optimization) focuses specifically on influencing how large language models represent a brand, topic, or entity within their trained parameters. Unlike AIO or GEO — which target real-time retrieval — LLMO is concerned with the model's underlying "knowledge" as baked in during training.
Why LLMO is difficult to control
LLMs are trained on massive datasets at infrequent intervals. Unlike a webpage that can be updated tonight and indexed tomorrow, a brand's representation inside a trained model is fixed until the next training run — which may be months away. Most "LLMO" work is therefore speculative.
What practitioners actually mean by LLMO
In practice, most agencies use "LLMO" to refer to content strategies that improve brand representation across the web sources LLMs train on — effectively the same as AIO/GEO. The distinction is theoretically meaningful but practically blurry.
Generative AI Search
The new paradigm — AI-synthesised answers replacing traditional search results
The paradigm shift
Generative AI Search describes the fundamental shift from search engines that index and rank to AI systems that read and synthesise. The user's query is no longer matched to documents — it is answered by a model that has read and processed vast amounts of the web.
The three layers of Generative AI Search
- Parametric knowledge — information encoded in the model's weights during training. Fast to retrieve, but potentially outdated.
- Retrieval-augmented generation (RAG) — real-time web search layered over the model. This is how Perplexity and ChatGPT Search work — the model retrieves live sources to ground its answer.
- Knowledge graphs — structured entity databases (like Google's Knowledge Graph) that AI models use to verify facts and relationships.
What this means for your brand
To influence a Generative AI Search result, you need to be present in all three layers: trained into the model's base knowledge through authoritative web presence, retrievable in real-time through well-indexed, citable content, and represented accurately in knowledge graphs through consistent structured data.
All the terms,
on one table.
| Term | Full name | Origin | Primary target | Distinct from SEO? | Measurable? |
|---|---|---|---|---|---|
| AIO | AI Influence Optimization | AI Search Lab | AI engine citations (real-time retrieval) | Yes — different signals | Yes — citation frequency |
| GEO | Generative Engine Optimization | Academic research (2023) | Generative AI responses broadly | Yes — content-focused | Partially |
| AEO | Answer Engine Optimization | Voice search era (2016+) | Direct answers, featured snippets | Adjacent — structured data focus | Yes — snippet wins |
| LLMO | Large Language Model Optimization | Industry usage (2023+) | Model training data representation | Yes — training layer | Difficult — indirect |
| SEO | Search Engine Optimization | Web era (1990s+) | Google/Bing ranking algorithm | Baseline — still relevant | Yes — rank, traffic |
| AI Search | AI-Powered Search | Industry descriptor | The overall paradigm shift | Replaces traditional search | N/A — category term |
Now you know the terms.
Ready to rank in all of them?
AI Search Lab is the only team that built the methodology, publishes the research, and delivers the results — across every AI platform your buyers are using.