Glossary

The jargon decoder

Most of these acronyms describe the same job: making sure AI tools can find, understand and cite your site. Here's what each one means and whether you need to care.

ACPVerdict: Watch: Also: Agentic Commerce Protocol; OpenAI and Stripe's protocol for purchases inside ChatGPT.; Still exists after OpenAI moved most purchases back to merchant apps and sites in March 2026. Worth knowing about, not worth building for unless you're a large merchant.
AEO: Also: Answer engine optimization; Optimizing to be the answer, not just a link.; An older term from the featured-snippet and voice-assistant era, now applied to AI answers. Same job as GEO, slightly different emphasis on direct, question-and-answer content.
Agentic commerceVerdict: Watch: Also: AI shopping agents; AI assistants that research, compare and buy products for people.; Moving fast and messy: Shopify launched Agentic Storefronts and opened its Catalog in January 2026, while OpenAI scaled back in-chat checkout in March 2026. The constant underneath: clean, complete, real-time product data.
AI crawler: Also: AI bot; A bot that fetches web pages for an AI company.; Two main kinds: training crawlers (like GPTBot or ClaudeBot) that collect pages to train models, and search and user crawlers (like OAI-SearchBot, ChatGPT-User or PerplexityBot) that fetch pages to answer a question right now. Most don't run JavaScript, which matters a lot for headless and app-style sites.
AI ModeVerdict: Watch: Google's full chat-style search experience.; A separate tab and mode where Google answers conversationally and does multiple searches behind the scenes. Google reports a large audience; panel data shows a much smaller share of actual searches so far.
AI OverviewsVerdict: Do it now: Also: AIO, SGE; The AI-written summary at the top of many Google results.; Reaches over two billion people a month. When one appears, clicks to regular results drop sharply, and being cited inside it recovers some of that. Seer Interactive found organic click-through on informational queries of 3.35% with no AI Overview, 2.07% when the brand was cited in one, and 0.94% when it wasn't.
AI SEOVerdict: Do it now: Also: AI search optimization, AI optimization; The umbrella term: making your site findable, understandable and quotable by AI-powered search.; The plainest name for the whole field, and the one we use most on this site. It covers getting cited in Google's AI Overviews and AI Mode, ChatGPT, Gemini, Perplexity and Copilot. Google's own position is that this "is optimizing for the search experience, and thus still SEO".
AI share of voiceVerdict: Do it now: Also: AI visibility; How often AI answers mention you compared with competitors.; The closest thing to a ranking report for AI search. You can track it by hand with a fixed list of prompts before paying for a tool. A 2026 survey found 71% of marketers don't track it at all.
AIO: Also: AI optimization, AI Overviews; Confusing on purpose? It means two different things.; Some people use AIO for "AI optimization" in general. Others use it as shorthand for Google's AI Overviews. Check which one someone means before you agree to anything.
GEO: Also: Generative engine optimization; Optimizing to be cited inside answers written by generative AI.; The most-searched of the new acronyms, with roughly twice the search demand of AEO in early 2026. In practice it means the same work as AI SEO: be the clearest, most trustworthy source on a topic, and make sure AI crawlers can read you.
LLMO: Also: Large language model optimization; Optimizing how large language models describe your brand.; Often used for the brand side of the work: what ChatGPT or Claude say about you when asked, even with no web search involved. Useful idea, clunky name.
llms.txtVerdict: Watch: A proposed text file that gives AI models a map of your site.; Cheap to add and many plugins generate one, but Ahrefs found 97% of llms.txt files got zero requests in May 2026, and Google says no special AI files are needed. Fine to have, not worth paying for.
NLWebVerdict: Skip: Microsoft's open project for adding a natural-language interface to websites.; Launched with partners including Shopify and Tripadvisor. There's no public count of real deployments yet.
Structured dataVerdict: Do it now: Also: Schema, Schema.org, JSON-LD; Code that labels what a page is about: an article, a product, an organization.; Still the way to earn rich results in Google, and it helps machines connect your brand, people and products. An Ahrefs test of 1,885 pages found no meaningful lift in AI citations from adding it, so do it for the right reasons.
SXO: Also: Search experience optimization; SEO plus user experience: ranking and then actually satisfying the visitor.; Predates AI search, but matters more now: when fewer people click, the ones who do arrive further along and expect the page to deliver immediately.
UCPVerdict: Watch: Also: Universal Commerce Protocol; Shopify and Google's open standard for AI agents to shop and check out.; Announced in January 2026. Lets agents discover products and complete purchases across merchants. Shopify merchants get much of it through the platform; others need to integrate.
WebMCPVerdict: Watch: A browser standard that lets a website hand AI agents real functions to call.; Instead of an agent guessing at buttons, the site exposes actions like "search products" or "book a time". In preview in Chrome, with a Cloudflare developer preview. Early, but the direction is real.
Zero-click searchVerdict: Do it now: A search that ends without anyone clicking a result.; About 68% of US Google searches in early 2026, up from about 60% in 2024 (SparkToro data). The reason traffic can fall while rankings hold steady.