Resources · Glossary

The eCommerce Insights glossary of AI-search terms.

Thirty definitions for GEO, AEO, ACO, LLM SEO, and the practitioner terms around them. eCommerce Insights stays neutral on the naming war and tries to get each term right.

30 terms · Last updated 2026-04-18


Core category terms

The terms the industry uses to name this whole space. eCommerce Insights uses GEO as the umbrella when forced to pick, defines AEO as Answer Engine Optimization by default, and treats ACO as 's coined term for the ecommerce-specific slice.


eCommerce Insights terms

The seven phrases eCommerce Insights uses to describe what changes when you track AI visibility at SKU granularity instead of brand granularity. Two are wedge terms eCommerce Insights owns; the others are industry phrases eCommerce Insights defines precisely.


Practitioner terms

The vocabulary SEO practitioners, analysts, and AI-search vendors actually use day-to-day. eCommerce Insights defines each neutrally and notes when the term is contested or newly coined.

PRACTITIONER

Citation analysis

Examining which URLs and sources AI engines cite in answers, for which queries, and how often.

PRACTITIONER

Brand mentions

Raw count of a brand's appearances in AI answers, whether or not they resolve to a specific product.

PRACTITIONER

Prompt monitoring

Tracking a fixed set of prompts across AI engines over time to detect shifts in how they're answered.

PRACTITIONER

Prompt tracking

Synonym for prompt monitoring. The term practitioners use for rank-tracking's AI-era analogue.

PRACTITIONER

Share of model

A brand or product's share of mentions inside a given AI engine's answers, relative to a defined competitive set.

PRACTITIONER

Share of voice (AI)

Share-of-voice adapted to AI: a brand's percentage of total mentions within a tracked prompt set.

PRACTITIONER

Hallucination detection

Finding AI-generated claims about a brand or product that aren't true — wrong specs, wrong price, wrong feature set.

PRACTITIONER

AI sentiment

The tone — positive, neutral, negative — of how AI engines characterize a brand or product across prompts.

PRACTITIONER

AI reputation

The aggregate impression of a brand across AI engines: what they say, how often, and with what sentiment.

PRACTITIONER

AI traffic analytics

Attribution and behavior analysis for visits that originate from AI-engine answer clicks.

PRACTITIONER

llms.txt

A proposed plain-text file served at the site root that gives AI crawlers a curated summary of the site.

PRACTITIONER

Query fan-out

An AI engine expanding a user's single query into several sub-queries to assemble a richer answer.

PRACTITIONER

Agentic commerce

Commerce conducted by or mediated through AI agents — recommendation, comparison, and increasingly purchase.

PROTOCOL

ACP (Agentic Commerce Protocol)

OpenAI/Stripe/Meta open spec, Apache 2.0. Powers ChatGPT Instant Checkout. Five merchant endpoints plus Stripe Delegate Payment.

PROTOCOL

UCP (Universal Commerce Protocol)

Google-led open spec announced 2026-01-11 with Shopify, Etsy, Wayfair, Target, Walmart. Often misnamed "Unified Content Protocol" in early coverage.

PRACTITIONER

Shopify Agentic Storefronts

Shopify's channel that wraps UCP and the OpenAI relationship for Shopify merchants. Documented at shopify.dev/docs/agents.

PROTOCOL

AP2 (Agent Payments Protocol)

Google's sister protocol to UCP. UCP orchestrates lifecycle; AP2 handles secure agent-led payments.

PROTOCOL

Vault token (vs SPT)

SPT is the credential type name in ACP. Vault token (vt_...) is the artifact Stripe issues at /delegate_payment.

PRACTITIONER

Agentic Readiness Report

A per-SKU readiness score for whether an AI shopping agent could evaluate, compare, and recommend the product.

PRACTITIONER

PDP optimization

Improving a product-detail page's content, schema, and metadata so it performs better in both human and AI search.

PRACTITIONER

Product schema

Structured data marking up a product: name, SKU, GTIN, brand, price, availability, and review signals.


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The category still argues about names. eCommerce Insights keeps the definitions current and linked, so your team has one reference they can trust.