Originally published on rikuq.com. Republished here for Dev.to's readers.
Marketing teams now routinely encounter five terms used interchangeably (and incorrectly) in the AI search space: SEO, AIO, SGE, AEO, and GEO. Most are the same idea wearing different industry hats. A few mean something genuinely different. One is already dead.
Here is the plain-English glossary, with the one distinction that actually matters at the bottom.
TL;DR
| Term | What it is | Status in 2026 |
|---|---|---|
| SEO | Optimizing for traditional search engines (Google blue links, Bing) | Still ~70% of organic traffic for most businesses |
| AIO | Optimizing for Google's AI Overview feature | Live, growing, increasingly important |
| SGE | Google's old name for AIO during the experimental phase | Dead term — Google renamed it AI Overview in 2024 |
| AEO | Answer engine optimization — getting cited by ChatGPT / Perplexity / Claude | Active, narrower than GEO |
| GEO | Generative engine optimization — the umbrella covering AIO + AEO + LLM citation work | Current professional usage |
| LLM SEO / AI SEO | Marketing-speak synonyms for GEO | Acceptable but less professional |
Why this is confusing
Three industries (search, marketing tech, AI tooling) started inventing terminology for the same underlying phenomenon at the same time. Each industry had its own incumbents promoting their preferred term. Google pushed SGE then AIO. Marketing agencies pushed AEO. AI-tooling startups pushed GEO. Nobody owned the category, so the terms multiplied.
The good news: by mid-2026 the field is converging on a smaller set. GEO is becoming the umbrella term professionals use; the platform-specific names (AIO for Google, "ChatGPT optimization" for ChatGPT) are emerging where the practitioner needs to specify.
Below is each term explained as briefly as possible.
SEO (the baseline)
Search Engine Optimization. The original, oldest term. Means optimizing your content and technical setup so that traditional search engines (Google, Bing, DuckDuckGo) rank your pages well in the blue-link results.
Practitioners spent the last 25 years building this discipline. The core mechanics — content relevance, technical SEO (page speed, clean HTML, schema, internal linking), backlinks, brand authority — all still matter.
What changed in 2024-26: SEO is no longer the only game. AI search engines now consume a significant fraction of buyer-intent search behavior. They have their own ranking signals. SEO best practices are 70-80% transferable to AI search but not 100%. The remaining 20-30% gap is what GEO covers.
AIO — Google AI Overviews
Google's AI-generated answer that appears at the top of search results for many queries. Launched as SGE in 2023, renamed AI Overview in 2024, now a permanent feature of Google search.
AIO pulls citations from Google's indexed web (the same crawl as classical SEO) but uses different ranking signals than blue-link results. A page can rank #1 in blue links and still be invisible in AIO citations. A page can be cited heavily in AIO and not rank in the top 10 organic results.
Optimizing for AIO specifically: clean schema, FAQPage markup, answer-shaped content (questions stated explicitly, then answered concisely), strong entity SEO (your brand recognized as an entity), and presence on the aggregator + third-party sources that AIO frequently cites.
AIO is one specific platform within the broader GEO discipline. When practitioners say "AI search optimization" they often mean AIO specifically because Google's traffic share dwarfs the other AI platforms today.
SGE — the dead term
Search Generative Experience. Google's experimental name for AIO during 2023-2024. When Google made the feature permanent in 2024, they rebranded to AI Overview.
If you see SGE in 2026 content, the content is either pre-2024 or written by someone who didn't update their vocabulary. Don't use it. Use AIO.
AEO — Answer Engine Optimization
Optimizing your content to be cited by AI answer engines (ChatGPT, Perplexity, Claude with browsing). Coined around 2023 by marketing agencies looking for a category name that wasn't tied to Google.
AEO is narrower than GEO in common usage: most practitioners use AEO specifically for the answer-engine-style platforms (ChatGPT, Perplexity, Claude), and GEO as the umbrella that includes AIO + AEO together.
The mechanics: schema markup, brand authority signals, presence on the third-party sources LLMs are trained on (Reddit, Wikipedia, major publications, aggregators). Same as GEO, just with a slightly different historical lineage.
GEO — Generative Engine Optimization
The umbrella term for optimizing any content to be cited by any generative AI search platform. Includes AIO + AEO + future AI search interfaces. Coined around 2024, adopted broadly by 2025-26.
GEO is what most professionals use as the default category name today. It's broader than AEO (includes Google AIO) and broader than AIO (includes the non-Google platforms). When someone says "we're doing GEO work" in 2026, they generally mean a comprehensive AI search visibility program across the major platforms.
LLM SEO / AI SEO
Marketing-speak synonyms for GEO. Equally correct, less common in professional usage. "LLM SEO" emphasizes that the optimization targets large language model retrieval. "AI SEO" is the broadest possible framing.
Both terms are used interchangeably with GEO in casual conversation. In professional documents, GEO is increasingly the standard.
The one practical distinction that actually matters
Forget the alphabet soup for a moment. The distinction that drives every meaningful optimization decision is this:
SEO targets Google's blue-link crawler. GEO targets a multi-platform citation graph that's only partly powered by Google's crawler.
That difference creates real, measurable gaps. In our 25-brand audit across the 5 major AI search platforms, we measured surface-rate gaps of up to 40 percentage points between branded vs unbranded queries, and per-brand gaps of up to 80 percentage points between AIO and ChatGPT for the same brand on the same query.
Translation: the same content can rank perfectly in Google blue links, get cited in AIO, and be completely invisible to ChatGPT. Or vice versa. Each AI search platform behaves differently, and SEO best practices alone don't cover any of them fully.
That's why GEO exists as a separate discipline. It's not a rebrand of SEO. It's the additional optimization work needed to be cited across the 4-5 AI search platforms that Google's classical crawler doesn't fully serve.
What to optimize for first
If you're starting GEO work and don't know which platform to prioritize, the data-backed answer is:
Google AI Overview (AIO) first. Highest US traffic volume of any AI search surface. Your existing SEO investment partially transfers. Focus on FAQPage schema, entity SEO, and answer-shaped content. Read Google's official AEO guidance and our breakdown of what Google's May 2026 guidance actually changed.
ChatGPT second. Largest pure-AI-search audience by user count. Citation behavior differs from AIO. Long-form earned content (substantive blog posts, deep reviews, Reddit discussion presence) carries more weight than short SEO-flavored content.
Perplexity third. Smaller audience but higher conversion (users actively researching). Favors structured, well-cited content that looks like Wikipedia in shape.
Gemini fourth. Increasingly aligned with AIO since it's the same Google ecosystem. Optimizing for AIO often improves Gemini surface as a side effect.
Claude with browsing fifth. Newest and most volatile. Citation behavior changes weekly as Anthropic iterates the feature.
The honest read: most teams don't have the bandwidth to optimize for all 5 simultaneously. Pick the top 2 your buyers actually use, measure your current surface rate per platform, and prioritize the platform where the gap between your blue-link rank and your AI citation rate is largest. That's the biggest free win available.
What's next
- The full data behind these claims: The Indian AI Search Audit (May 2026) — 25 brands, 500 queries, 777 citations.
- Why the 5 AI search platforms behave so differently from each other: The Four-Index Reality.
- Google's official position on AI search in May 2026 vs what holds up across other platforms: GEO vs SEO in 2026 — What Google's May Guidance Changed.
- An honest comparison of the AI search visibility tools you can buy: AI Search Visibility Tools: Honest Comparison From a Builder.
If the alphabet soup is keeping your team from acting, just pick GEO as your working term, start measuring on the 2 platforms your buyers use most, and let the terminology debate continue in the background. The decisions you make from real per-platform data will matter more than the labels.
