The CSToday glossary

Glossary

Definitions of the AI visibility, LLMO, and answer-engine terms that show up across the field guide, the blog, and the tools bench. Each entry opens with a citable capsule.

Crawlers

  • AI Crawler

    An AI crawler is an automated program that visits websites on behalf of a large language model or answer engine to collect, render, and index content for retrieval-augmented generation or training. Unlike traditional search crawlers, AI crawlers often execute JavaScript, respect llms.txt directives, and prioritize structured data to build citable answer passages.

  • Crawler Rendering

    Crawler rendering is the process by which an AI crawler or search bot executes JavaScript on a page to construct the final DOM before extracting content. Many AI crawlers still fetch only raw HTML, so any content loaded or modified by client-side scripts remains invisible to them unless the server delivers a fully rendered snapshot.

  • Training vs Retrieval Crawlers

    Training crawlers and retrieval crawlers serve fundamentally different purposes in AI systems. Training crawlers ingest public content to build model weights during pre-training. Retrieval crawlers fetch live pages at query time to ground answers in current sources. Understanding the distinction determines which controls you apply to your site.

Protocols

  • Canonical URL

    A canonical URL is the single, authoritative version of a page that search engines and AI crawlers should index and cite. It resolves duplicate content by telling systems which URL represents the primary resource, consolidating ranking signals and citation eligibility to one address.

  • IndexNow

    IndexNow is an open protocol that lets websites notify participating search engines the moment a URL is added, changed, or removed. Instead of waiting for crawlers to discover updates, the site pushes a lightweight ping so the index reflects the current state within minutes.

  • llms.txt

    llms.txt is a proposed plain-text file placed at a site root that tells large language models which pages to read, which to skip, and how to interpret the site's structure. It gives publishers a direct signal to crawlers such as GPTBot, ClaudeBot, and PerplexityBot, complementing robots.txt and sitemaps for the answer-engine era.

  • Schema.org

    Schema.org is a shared vocabulary of structured data types that lets websites describe their content in a format search engines and AI systems can read directly. By adding JSON-LD markup to pages, law firms and healthcare practices tell crawlers exactly what each entity is, such as an attorney, service, review, or location, so answers can cite the source with precision.

Metrics

  • Citation-Worthiness

    Citation-worthiness is the quality that makes a web page likely to be quoted or referenced by AI answer engines. It depends on clear structure, verifiable claims, authoritative sourcing, and semantic clarity so that models can extract and attribute passages confidently. Pages with high citation-worthiness appear in AI Overviews, ChatGPT responses, and Perplexity answers.

  • Share of Model

    Share of model measures how often a brand appears in the answers generated by large language models across a defined set of prompts. It is the answer-engine counterpart to search share of voice, tracking whether your firm or practice is cited when prospective clients ask AI systems for recommendations in your practice area.

Concepts

  • Answer Capsule

    An answer capsule is a 40 to 60 word self-contained passage that directly answers a specific question at the top of a page. It gives AI systems a citation-ready snippet they can quote verbatim in generated answers. Every CSToday glossary page opens with one.

  • Entity (and Entity Optimization)

    An entity is a distinct, named concept such as a person, organization, location, service, or legal topic that AI systems recognize and disambiguate through structured data and consistent citations. Entity clarity lets models associate your firm or practice with the right practice areas, jurisdictions, and trust signals so you appear in answers rather than adjacent noise.

  • Generative Engine Optimization / Answer Engine Optimization (GEO / AEO)

    GEO and AEO refer to the practice of structuring digital content so that generative AI systems and answer engines can find, understand, and cite it in synthesized responses. Unlike traditional SEO which targets link rankings, these disciplines target inclusion in AI-generated answers across platforms such as ChatGPT, Perplexity, and Google AI Overviews.

  • Hallucination

    A hallucination is a confident but fabricated response from a large language model that presents invented facts, citations, or reasoning as if they were real. It occurs because models predict plausible token sequences rather than retrieve verified knowledge from a trusted source.

  • Large Language Model Optimization (LLMO)

    LLMO is the practice of structuring a website so AI systems can find, understand, and cite its content in answers. It replaces traditional search optimization for the answer-engine era by focusing on citation-worthiness, entity clarity, and crawler accessibility rather than keyword rankings.

  • Retrieval-Augmented Generation (RAG)

    Retrieval-Augmented Generation (RAG) is an AI architecture that grounds model output in external knowledge by retrieving relevant documents before generating an answer. Instead of relying solely on training data, the system searches a knowledge base, passes the retrieved passages to the model, and produces a response that cites or reflects those sources. This reduces hallucination and makes output verifiable.

  • Zero-Click Search

    Zero-click search occurs when a search engine or AI answer engine delivers a complete answer directly on the results page or in a generated response so the user does not need to click through to a source site. The answer is extracted, summarized, or synthesized from indexed content and presented inline.

Products

  • AI Overviews

    AI Overviews are Google's generated answer summaries that appear at the top of search results, synthesized from multiple web sources and presented with inline citations. They replace traditional featured snippets for many queries and represent Google's shift from link lists to direct answers.

Security

  • Credential Stuffing

    Credential stuffing is an automated attack that tests username and password pairs from prior breaches against login portals to gain unauthorized access. It exploits password reuse across services and remains a primary vector for account takeover in law firms and healthcare practices.

  • HIPAA and AI

    HIPAA and AI describes the compliance intersection where protected health information meets large language models. Any prompt, training run, retrieval pipeline, or crawler interaction that touches PHI triggers HIPAA obligations: business associate agreements, minimum necessary access, audit controls, and breach notification. Regulated practices must govern AI use without surrendering AI visibility.

  • Multi-Factor Authentication (MFA)

    Multi-factor authentication requires two or more independent credentials from different categories to verify identity. It combines something you know, something you have, and something you are, making credential theft alone insufficient for account compromise, because a stolen password still leaves the remaining factors unsatisfied.

  • Prompt Injection

    Prompt injection is an attack that hijacks a language model's behavior by embedding malicious instructions in user input or retrieved data. The model treats the injected text as part of its prompt, overriding original instructions or safety controls. It is the primary security risk in retrieval-augmented systems and AI agents.

  • Server-Side Request Forgery (SSRF)

    Server-Side Request Forgery (SSRF) is a vulnerability class where an attacker induces a server to make unintended outbound requests, often to internal services or metadata endpoints. In the context of AI visibility, SSRF risk arises when crawler-rendering pipelines or LLM tool-use features fetch attacker-supplied URLs without adequate validation, potentially exposing internal infrastructure or credential material.