If you’ve been to a conference, sat through a vendor pitch, or scrolled LinkedIn in the last 18 months, you’ve been hit with a wave of acronyms: GEO, AEO, AIO, LLMO, AISEO. Everyone seems to be using them. Almost no one is using them the same way. (Or accurately, but that’s a topic for another post…)

This isn’t a sign that AI search is unstable or overhyped. It’s a sign that the field is moving faster than the language describing it. The underlying strategy is more consistent than the terminology suggests, but the terminology chaos creates real problems when law firm marketing teams are trying to evaluate vendors, build internal alignment, or justify budget to firm leadership.

This glossary cuts through the noise. Here’s what each term actually means, where it came from, how they relate to each other, and—most importantly—what it means for how your firm shows up when a prospective client asks an AI tool for a lawyer.

Why There Are So Many Terms (And Why That’s Not Your Fault)

The AI search optimization discipline is genuinely new. The paper that formally named and defined “Generative Engine Optimization” was published in November 2023 by researchers at Princeton University, Georgia Tech, the Allen Institute for AI, and IIT Delhi, and it didn’t appear in a major conference until 2024. That means the entire field, as a recognized practice, is barely two years old.

There is no governing body. No standards organization. No agreed-upon taxonomy. Agencies named the same phenomenon differently as it emerged, often based on what search terms they wanted to rank for. The result is that a prospect can talk to four different providers about the same strategic problem and hear four different acronyms—none of them wrong, all of them describing overlapping territory.

The good news is that the underlying signals AI systems use to evaluate content are far more stable than the terminology. Build the right foundation, and you’re positioned well regardless of what the industry settles on calling it. Understanding the terms helps you have smarter conversations about the work—not replace the work itself.

The Terms, Defined

SEO — The Baseline You Already Know

Search Engine Optimization (SEO) is the practice of optimizing a website’s content, technical structure, and authority signals so that traditional search engines surface it in ranked results for relevant queries.

SEO is worth defining explicitly here because everything else in this list builds on it, not away from it. The firms that will perform best in AI-driven search are the ones with strong SEO foundations, not the ones who abandoned SEO in favor of the next shiny acronym.

At 9Sail, our position is unambiguous: good SEO is the prerequisite for good GEO. The same content quality, authority signals, and technical infrastructure that drives organic rankings is what makes AI engines choose to cite you.

GEO — Generative Engine Optimization

GEO is the most precise and strategically useful umbrella term currently in use. It was coined by researchers from Princeton, Georgia Tech, the Allen Institute for AI, and IIT Delhi in a 2023 paper presented at ACM KDD 2024—the first peer-reviewed academic research to formally define and measure this discipline.

The core idea is this: traditional SEO optimizes for ranking in a list of links. GEO optimizes for being cited in a synthesized answer. The output interface has changed. When someone asks ChatGPT, Perplexity, or Google AI Overviews a question about legal representation, they don’t see ten blue links on a search engine results page (SERP), they see a generated response that pulls from sources the AI system deems authoritative. GEO is the practice of making your firm one of those sources.

What GEO actually involves in practice: structured content creation, entity recognition, semantic richness, citation density, consistent authority signals across all digital properties, and third-party mentions from sources AI systems trust. The Princeton research found that content modifications aligned with these principles can improve AI visibility by up to 40%.

For law firms specifically, GEO isn’t a nice-to-have. Legal queries are disproportionately answered by AI because they’re complex, question-based, and high-stakes. Meaning, they are exactly the type of query generative engines are designed to handle. When someone asks “Do I need a business attorney to form an LLC?” AI engines are generating the first response that prospect sees. GEO determines whether your firm is in that response.

AEO — Answer Engine Optimization

AEO is the older term, and its meaning has shifted over time. It originated around 2017 with the rise of featured snippets and voice search, before generative AI was a mainstream reality. The original idea was straightforward: structure your content to directly answer discrete questions so search engines would surface it as the immediate response.

Today, AEO is used interchangeably with GEO by many practitioners. Technically, it’s a subset. If GEO is the overarching strategy, i.e. build the authority and structure that makes AI choose to cite you, then AEO is one tactic within it: organizing content at the paragraph and subheading level so AI systems can cleanly extract direct answers.

The practical distinction for law firms: AEO-oriented content answers “Can I sue my employer for wrongful termination in Pennsylvania?” with a clear, structured response in the first two sentences—not a buried conclusion after five paragraphs of background context. That structural discipline is what makes content extractable by AI, and extractability is a prerequisite for citation.

When a vendor says they do “AEO,” ask them specifically what they mean. If they’re talking about answer-structured content and schema markup, that’s a legitimate and valuable tactic. If they’re using it as a standalone service description that doesn’t connect to broader authority building, that’s a narrower play than what your firm likely needs.

AIO — AI Overviews (Google-Specific)

This is the term that causes the most confusion, and it’s worth being precise: AIO is a product name, not a strategy term. It refers specifically to Google’s AI-generated summary blocks that appear at the top of search results: the synthesized answers that now appear for a significant percentage of legal queries on Google.

Some practitioners use AIO to mean “AI Optimization” broadly, as in a general umbrella for everything in this list. That’s a different and conflicting usage. When 9Sail uses AIO, we mean Google’s AI Overviews product specifically.

Why this distinction matters: optimizing for AIO involves the same foundational signals as GEO—authority, structured content, entity recognition—but with specific attention to how Google’s AI surfaces and attributes sources within its own search environment. It’s a subset of GEO, scoped to Google.

For most law firms, AIO should be the first focus. Google remains the dominant search entry point for legal queries, and AI Overviews appearing at the top of results for high-intent searches directly displaces the organic rankings firms have spent years building. Getting cited in AIO means your firm captures the prospect before they ever scroll to the traditional results.

AISEO — AI Search Engine Optimization

AISEO is a catch-all hybrid term with no standard definition. It blends familiar SEO vocabulary with AI terminology, which makes it comfortable-sounding and therefore popular in some vendor marketing. According to research analyzing social media engagement trends in late 2025, AISEO sits at the top of engagement metrics—which tells you more about what performs well in LinkedIn headlines than about strategic precision.

When you encounter AISEO, treat it as a signal that the speaker may still be developing their framework. Ask: “What specifically are you optimizing, and which platforms are you targeting?” The answer will tell you quickly whether there’s a real strategy underneath the acronym or whether it’s a repackaging of existing services with new vocabulary.

SGE — Search Generative Experience

SGE was Google’s internal name for what became AI Overviews during its testing phase in 2023 and 2024. The name was retired when the product launched publicly. If you see SGE in a vendor proposal, an agency’s service page, or older blog content, substitute “AI Overviews.” It means the same thing. The persistence of SGE in some agency materials is a reasonable proxy for how recently those materials were updated.

Zero-Click Optimization

Zero-click isn’t a new acronym, but it’s a critical strategic concept that underlies all of the above. A zero-click search is one where the user gets their answer without clicking through to a website. AI Overviews, featured snippets, and knowledge panels are the primary zero-click surfaces for legal queries.

For firms that have measured their success primarily through organic traffic and click-through rates, zero-click optimization requires a mental model shift: the goal isn’t always to drive the click. Sometimes the goal is brand impression, authority attribution, and being the voice that answers the prospect’s question, even if they never visit your site. The firms that resist this shift will continue optimizing for a metric (organic traffic) that is structurally declining as AI handles more queries directly.

Entity Optimization

Entity optimization is foundational to every term on this list, and it predates the AI search era, though it matters more now than it ever has. An entity, in the way Google and AI systems think about it, is a recognized object in the world: a person, an organization, a place, a concept. Your firm is (or should be) an entity. Your attorneys are entities. Your practice areas are entities.

AI models reason about entities and the relationships between them, not just about keywords. When an AI system decides whether to cite your firm, it’s partially evaluating whether your firm is a clearly defined, consistently recognized entity with sufficient authority signals in its domain. Inconsistent NAP data across directories, attorney profiles that don’t include credentials and outcome information, and absence from industry publications all create entity ambiguity, which makes AI systems less confident citing you.

Practical implications: audit your firm’s entity signals before you build any other GEO program. This means consistent firm name, address, and phone number across every directory and listing; structured attorney profiles with credentials, bar admissions, and documented expertise; and a presence on the publications and directories AI systems use to validate authority in legal services.

How These Terms Relate to Each Other

The alphabet soup is easier to navigate with a simple mental model. Think in three tiers:

Foundation — SEO. The technical and content bedrock that everything else requires. Strong content, clean site architecture, quality backlinks, entity consistency. Without this, nothing above it works.

Strategy — GEO. The umbrella approach for AI visibility across all platforms. Encompasses content structure, authority building, semantic richness, and citation signals. AEO, LLMO, and AIO optimization are all execution layers within GEO.

Entity Optimization.

Platform-specific execution — AIO and targeted channel work. Google AI Overviews require attention to Google-specific signals. AI assistant visibility requires a different distribution strategy. Each platform has nuances, but the underlying authority logic is consistent.

These aren’t sequential phases or competing approaches. A firm with strong SEO foundations that implements GEO strategy will see benefits across Google AIO, AI assistants, and traditional organic rankings simultaneously because the same signals drive all of them.

What This Means in Practice for Your Firm

Most law firm websites were not built with AI citation in mind. Historically, law firm digital strategy has prioritized clean, professional presentation over content depth. This is particularly true for Am Law 100 and 200 firms, where intentionally sparse websites have been the norm. That approach made sense when rankings were determined by link authority and keyword relevance. It creates a significant GEO vulnerability in the current landscape.

The firms showing up in AI answers today aren’t necessarily the biggest or best-funded. They’re the ones whose content is structured, authoritative, and semantically rich. A well-optimized regional firm with deep practice area content can outperform a national firm with a thin website in AI-generated responses, because the AI is evaluating source quality, not firm size.

Three questions worth answering honestly before your next planning conversation:

1. What does your firm look like in AI? Open ChatGPT or Perplexity and ask about your primary practice area in your market. If your firm isn’t mentioned, or is mentioned with incomplete or incorrect information, that’s your baseline.
2. Are your attorney profiles structured for AI extraction? Narrative paragraphs don’t extract cleanly. Profiles with clearly labeled credentials, bar admissions, practice focuses, and documented outcomes do.
3. Is your entity presence consistent? Run your firm name across your top five directories and your own site. Inconsistencies in firm name, address, phone number, or practice area descriptions create entity ambiguity that reduces AI confidence in citing you.

One Final Note on Service Provider Conversations

The terminology in this space will continue to evolve. New platforms will emerge, new acronyms will follow. The useful filter isn’t which term a vendor uses, it’s whether they can explain specifically what they’re optimizing, why it increases citation probability, and how they measure whether it’s working.

The foundational signals AI systems use to evaluate authority are stable: quality content, entity recognition, structured data, and credible third-party citations. Firms that build those foundations, and work with partners who understand the legal-specific nuances of how AI systems handle YMYL content, will be well-positioned regardless of what the industry decides to call it next.