A

Agent Experience (AX)

Agent experience is how easy a company makes it for AI agents to read its information, use its services and complete a task.

Agentic Checkout

Agentic checkout is a purchase flow where an AI agent places the order on a shopper's behalf instead of the shopper filling in a checkout form.

Agentic Commerce

Agentic commerce is buying and selling where an AI agent does the searching, comparing and often the purchasing on a person's behalf.

Agentic Commerce Protocol (ACP)

The Agentic Commerce Protocol is an open specification from OpenAI and Stripe for how an AI agent and a merchant exchange checkout and payment information.

Agentic Search

Agentic search sends an AI assistant through its own sequence of searches and page reads before it answers, planning each step as it goes.

Agentic Storefront

An agentic storefront is the machine-readable version of a shop: products, prices, stock and terms exposed so an AI agent can browse and select.

agents.md

agents.md is a Markdown file in a code repository that tells AI coding agents how to build, test and work with that project.

AI Answer Engine

An AI answer engine is a search system that retrieves passages from live web sources and uses a language model to write one cited reply.

AI Brand Sentiment

AI brand sentiment is the tone an AI assistant takes when it describes your brand in a generated answer: positive, neutral, negative or mixed.

AI Crawler

An AI crawler is an automated client that fetches web pages for an AI company, either to train a model or to source a live answer.

AI Overview

An AI Overview is the summary Google writes above its regular search results, built from web pages and shown in place of the top links.

AI Search

AI search is the category of search products that answer a question in written prose instead of returning a list of links.

AI Search Impression

An AI search impression is one instance of your brand appearing inside a generated answer, counted once per answer rather than once per link.

AI Search Optimization (AISO)

AI Search Optimization (AISO) is the practice of making a brand findable and quotable across AI search surfaces, from ChatGPT to Google's AI Mode.

AI Search Ranking

AI search ranking is the scoring step that decides which retrieved passages reach the model before an answer is written.

AI Search Traffic

AI search traffic is the visitors who reach your site from a link inside an AI assistant's answer.

AI Shopping Agent

An AI shopping agent is software that carries out a shopping task for a person: interpreting the brief, searching, comparing and sometimes buying.

AI-Attributed Conversion

AI-attributed conversion is a sale or signup credited to a visit that began with an AI assistant naming your brand.

AI-Generated Answer

An AI-generated answer is the text an assistant writes in reply to a question, assembled from retrieved sources rather than copied from one.

Answer Engine

An answer engine resolves a question on the results surface, returning the answer itself rather than a list of documents to read.

Answer Engine Optimization (AEO)

Answer Engine Optimization (AEO) is the practice of writing pages so a search product can lift a direct answer from them and attribute it to you.

Answer-First Content

Answer-first content puts the direct answer in the opening lines of a page or section, before any background.

Author Authority

Author authority is the weight a search or AI system gives a page because of who wrote it and what else that person has published.

Authority Content

Authority content is material a category treats as a reference: the piece people link to, quote and check against when they want the facts settled.

B

Backlink

A backlink is a link on another website pointing at a page on yours, giving a crawler a route to follow and a ranking system a signal to count.

Brand Mention Optimization

Brand mention optimization is the work of getting your brand named inside AI answers, whether or not the answer links to your site.

Business-to-Agent (B2A)

Business-to-Agent is a label for selling to AI agents acting for customers, rather than to the customers directly.

C

ChatGPT Ads

ChatGPT Ads is the shorthand marketers use for paid placement inside ChatGPT, a category discussed and trialled far more than it is documented.

ChatGPT Search

ChatGPT Search is the feature inside ChatGPT that runs live web searches and writes an answer with links to the pages it used.

ChatGPT Shopping

ChatGPT Shopping is the set of features inside ChatGPT that surface products, compare them and, for eligible merchants, complete the purchase in chat.

Citation Magnet

A citation magnet is a page built to be named as the source in an AI answer, usually because it holds a fact nobody else publishes.

Citation Optimization

Citation optimization is the practice of making a page easy for an AI assistant to quote and attribute, so your domain appears as a named source.

Citation Rate

Citation rate is the share of tracked prompts where an AI assistant names your site as a source, expressed as cited prompts divided by total prompts run.

Cited Source

A cited source is a page an AI assistant names and links as the origin of a claim in its answer.

Content Chunking

Content chunking is the practice of writing a page as a series of self-contained blocks, each covering one idea under its own heading.

Content Freshness

Content freshness is how current the facts on a page are, and how recently the page was genuinely revised.

Context Window

A context window is the maximum amount of text a language model can hold at once, counted in tokens and shared by the prompt, the sources and the reply.

Conversational Commerce

Conversational commerce is selling through a chat interface, where a customer asks questions in natural language and a person or a bot answers.

Conversational Query

A conversational query is a search input written the way a person speaks, usually a full question, often followed by refinements in the same session.

Core Web Vitals

Core Web Vitals are three measurements Google uses to describe a page's real-world experience: loading speed, responsiveness and visual stability.

Crawlability

Crawlability is whether an automated client can reach a page on your site, fetch it, and receive readable content in the response.

D

Dark Traffic

Dark traffic is the visits your analytics files as direct because the referrer never arrived.

Deep Research

Deep research is a mode in an AI assistant that spends minutes rather than seconds on a question, running many searches and returning a long cited report.

Digital PR

Digital PR is earning coverage and mentions on other websites rather than buying space on them.

Domain Authority

Domain authority is a third-party score estimating how likely a website is to rank in search, calculated mostly from its backlink profile.

E

E-E-A-T

E-E-A-T stands for experience, expertise, authoritativeness and trust, the four qualities Google's quality raters use to judge a page.

Embedding

An embedding is a list of numbers that represents the meaning of a piece of text, placed so that texts with similar meanings sit close together.

Entity Footprint

An entity footprint is the full set of places a model has seen your brand described: your site, directories, review platforms, news and social profiles.

Entity Optimization

Entity optimization is the work of making a model recognize your brand as a specific thing with known attributes, not just a string that appears on a page.

Extractability

Extractability is how easily a machine can lift a clean, correct, self-contained answer out of a page.

F

Factual Density

Factual density is how many checkable statements a passage contains: names, dates, quantities, conditions and specifications.

FAQ Content Strategy

An FAQ content strategy is the deliberate use of question-and-answer blocks to cover the specific things buyers ask, not a catch-all list.

Featured Snippet

A featured snippet is the short extract Google places above the organic results to answer a query, pulled verbatim from a page it has indexed.

G

Gemini

Gemini is Google's family of AI models and the assistant app built on them, and the same models write the AI answers inside Google Search.

Generative Engine

A generative engine writes its answer with a language model instead of returning documents, using passages it just retrieved from the web.

Generative Engine Optimization (GEO)

Generative Engine Optimization is the practice of getting a brand cited inside the answers AI assistants write, rather than ranked in a list of links.

GEO Score

A GEO score is a composite number a vendor calculates to summarize how well a site is set up to be cited by AI assistants.

GEO vs SEO

GEO and SEO are two ways of earning search visibility for the same content: SEO competes for a ranking position, GEO for a mention in a written answer.

Google AI Mode

Google AI Mode is a tab inside Google Search that replaces the list of results with a written answer you can keep asking questions of.

Google SGE (Search Generative Experience)

Google SGE, or Search Generative Experience, was the opt-in Search Labs experiment that put a generated answer at the top of Google's results.

Google-Extended

Google-Extended is a robots.txt token, not a crawler, that controls whether Google may use your content to improve its Gemini models.

Grok

Grok is xAI's assistant, available inside X and as a standalone app, answering from the open web and from posts on X.

Grounding

Grounding is the practice of tying a model's answer to specific source documents so each claim traces back to something actually retrieved.

H

Hallucination

A hallucination is a confident statement from an AI model that is not supported by any source, and often not true.

Hybrid Search

Hybrid search runs a keyword search and a meaning-based search over the same content, then merges the two result sets into one ranking.

I

Indexability

Indexability describes whether a page, once fetched, is eligible to be stored in an index and returned in results.

Information Gain

Information gain is how much a page adds that is not already available in the other pages covering the same subject.

Instant Checkout

Instant Checkout is OpenAI's feature that lets a shopper buy a product from a participating merchant without leaving ChatGPT.

K

Knowledge Cutoff

A knowledge cutoff is the date after which a model's training data stops, so anything that happened later is absent from what the model learned.

Knowledge Graph

A knowledge graph is a database of real-world things and the links between them, holding your brand as an entity rather than a string.

L

Large Language Model (LLM)

A large language model is a system trained on huge amounts of text to predict the next piece of text, one fragment at a time.

LLM Advertising

LLM advertising is paid placement inside the answers an AI assistant writes, rather than alongside them in a separate list of results.

LLM Audit

An LLM audit checks what AI assistants currently say about a brand, which sources they draw on, and where those answers are wrong or missing.

LLM Visibility

LLM visibility is how often, and how favorably, a brand appears in the answers large language models write for real buyer questions.

llms-full.txt

llms-full.txt is a single plain text file holding the full content of a site's key pages, not just links to them.

llms.txt

llms.txt is a plain text file at your site root that tells AI systems which pages matter most and what your site is about.

Log File Analysis

Log file analysis is reading your web server's raw request records to see exactly which bots and visitors fetched which URLs, and when.

Long-Tail AI Query

A long-tail AI query is a long, specific question typed into an assistant, usually a full sentence with constraints attached rather than a few keywords.

M

Microsoft Copilot Search

Microsoft Copilot Search is Microsoft's assistant answering a question from live web results, with links to the pages behind the reply.

Model Context Protocol (MCP)

Model Context Protocol (MCP) is an open standard that lets an AI assistant call external tools and read external data through a defined interface.

Multi-Turn Conversation Modeling

Multi-turn conversation modeling is the practice of planning content for a whole exchange with an assistant rather than a single question.

N

Named Entity Recognition (NER)

Named entity recognition is the step where a system reads a piece of text and tags which words are names: people, companies, products, places.

O

Original Research

Original research is content built on data you collected yourself: a survey, a test, an analysis of your own operating records.

P

Parsnip vs Parsnipp

Parsnip with one P is the root vegetable. Parsnipp with two Ps is a software company working on generative engine optimization.

Passage Ranking

Passage ranking is the scoring step that puts individual chunks of text in order, so the best few paragraphs get handed to a model rather than whole pages.

Perplexity AI

Perplexity AI is a search product that answers a question in prose and numbers its sources inline as it writes.

Persona-Based Querying

Persona-based querying runs the same question as several different kinds of buyer, then compares the answers each version gets back.

Pillar Page

A pillar page is a single page that covers a whole subject at a broad level and links out to the deeper pages beneath it.

Product Feed Optimization

Product feed optimization is making a structured product data file accurate, complete and consistent so shopping channels and AI agents can read it.

Prompt Engineering (for Content)

Prompt engineering for content is the practice of writing and testing prompts against AI assistants to plan, check and stress-test what you publish.

Prompt Tracking

Prompt tracking records what AI assistants say when a fixed list of buyer questions is asked, run after run, so a brand can see whether it is named.

Prompt-to-Citation Funnel

The prompt-to-citation funnel is the sequence of stages between someone typing a question and your page being named as a source in the answer.

Q

Query Fan-Out

Query fan-out is the step where an assistant turns one question into several separate searches and writes a single answer from what they return.

R

Reasoning Model

A reasoning model is a language model that works through a problem in intermediate steps before committing to an answer.

Reranking

Reranking is the second pass over a set of search results, where a slower, more accurate model reorders the shortlist before anything reaches the answer.

Retrieval-Augmented Generation (RAG)

Retrieval-augmented generation is the pattern where a system searches a set of documents first, then hands what it found to a model to write the answer.

robots.txt

robots.txt is a plain text file at a site's root that tells each named crawler which paths it may request.

S

Search Engine Optimization (SEO)

Search engine optimization is the work of making a website rank in the unpaid results of a search engine like Google.

Search Engine Results Page (SERP)

A search engine results page, or SERP, is the page a search engine returns after a query, holding organic links, ads and whatever blocks it chooses to add.

Semantic Search

Semantic search finds content by comparing meaning rather than matching words, so a page about trainers can answer a question about running shoes.

Server-Side Rendering (SSR)

Server-side rendering (SSR) is building a page's HTML on the server so the response already contains the content.

Share of Model

Share of model is your share of the brand mentions an AI assistant makes when it answers a category question from what it already knows.

Share of Voice (AI Search)

Share of voice in AI search is the percentage of brand mentions inside a set of generated answers that belong to you rather than to a competitor.

Source Credibility Signals

Source credibility signals are the checkable properties of a page and its publisher that a retrieval system uses to decide whether to trust and cite it.