Definitions

Short explanations of the technical terms Silktide uses. Articles can link to these so readers can look up a term without leaving the page.

Title	Summary
Above the fold	Above the fold means the part of a page visible before any scrolling - the first screen a visitor sees. The term comes from newspapers, where the top half of the front page (above the physical fold) sold the paper.
Accessibility tree	The accessibility tree is the simplified version of a page that a browser builds for assistive technology. It contains each element's role, name, and state, but not its visual styling. If information is missing or wrong in the accessibility tree, a screen reader cannot present it, no matter how the page looks.
Accessible name	The accessible name is the name of a button, link, or form control as assistive technology announces it - what a screen reader speaks and what speech-recognition software matches voice commands against. It usually comes from the element's visible text, but ARIA attributes like aria-label can override it, which is why the name users hear can differ from the label they see.
Actual text	Actual text is a PDF feature that stores an element's exact wording on its tag, instead of relying on the characters drawn on the page. Assistive technology announces the stored wording in its place, while the page looks exactly the same.
AEO	AEO (Answer Engine Optimisation) is about making your website easy for AI assistants - ChatGPT, Perplexity, Gemini, Copilot, and similar tools - to read, trust, and cite when people ask them questions.
AI crawlers	AI crawlers are the automated programmes AI companies use to read the web, just as search engines use Googlebot. Each AI assistant relies on one or more of them:
AI credit	An AI credit is the unit Silktide measures metered AI work in. Your plan includes a number of credits each month, and work you ask the AI to do — a chat conversation, a commissioned report — draws them down. Usage shows what has been used and what is left.
AI optimizer	An AI optimizer is ongoing AI work your plan includes, which you allocate to the part of Silktide you want it to work on. Your plan includes a number of them, and you choose where each one goes. Governance and Analytics each have their own.
AI visibility	AI visibility is whether AI assistants mention, describe, and cite your brands when people ask questions in the Please provide the full list of product terms to translate. I only see a usage note for “workspace” you care about.
Alt text	Alt text (alternative text) is a written description attached to an image in HTML using the alt attribute. Screen readers read it aloud in place of the image, and browsers show it when the image fails to load, so it is essential for accessibility.
Annotation	An annotation is an interactive element positioned on top of a PDF page rather than being part of the page's drawn content: a link, a form field, a comment or sticky note, a stamp, or an embedded media player.
ARIA	ARIA (Accessible Rich Internet Applications) is a set of HTML attributes that describe what interface elements are and what they are doing, for the benefit of assistive technology. An attribute like aria-label=\"Search\" gives an icon-only button a name a screen reader can announce; role=\"dialog\" tells it a pop-up is a dialog.
Artefact	An artefact is the PDF format's term for content that is deliberately hidden from assistive technology: running headers and footers, page numbers, watermarks, background images, and decorative lines and shapes. A screen reader skips artefacts completely - they are not read aloud and cannot be turned back on by the reader - while the page looks exactly the same.
Assertion	An assertion is a checkable fact you declare about a brand so Silktide can check whether AI assistants get it right.
Assistive technology	Assistive technology is any software or hardware a person uses to make computers usable for people with disabilities. On the web, this includes screen readers, screen magnifiers, voice control, switch devices and keyboard-only navigation.
Audio description	An audio description is narration added to a video's soundtrack that describes important visual information - actions, scene changes, on-screen text - for people who are blind or have low vision.
Bounce rate	Bounce rate is the proportion of visits that end after a single page, with no further interaction. A high bounce rate can mean visitors did not find what they wanted — or that a single page answered their question completely, so consider it alongside the page's purpose, rather than as a judgement on its own.
Brand	A brand in Presence is a named entity you want to recognise in AI answers: a canonical name plus aliases. Your brand and a competitor are the same kind of record. Each workspace names one main brand it is about, and can mark others as yours so they count towards you. Everything else in that workspace is a competitor. You can file a brand under a parent so views of the parent include the child's mentions.
Cache	A cache is a store of previously downloaded content kept for reuse, so it doesn't have to be fetched again. Web browsers cache files such as images, stylesheets, and scripts; the website's server tells the browser how long each file may be kept, usually via the Cache-Control HTTP header, before it must be re-downloaded.
Call to action	A call to action (CTA) is the button or link that asks the visitor to take the next step - "Buy now", "Request a demo", "Sign up for free".
Canonical URL	A canonical URL is the one authoritative web address a page declares for itself, using a <link rel="canonical"> tag in the page's head:
CAPTCHA	A CAPTCHA is a challenge designed to tell humans and automated programmes apart, such as typing distorted characters or selecting matching images. CAPTCHAs are a barrier for many people, particularly those with disabilities, so accessibility guidelines restrict when and how they may be required.
Captions	Captions are synchronised text shown over video or audio that convey the dialogue plus meaningful sounds - who is speaking, music cues, alarms, laughter. They exist so people who are deaf or hard of hearing can follow the media.
CDN	A CDN (content delivery network) is a service that delivers your website's files from servers close to each visitor, making pages load faster worldwide. Cloudflare, Fastly and Akamai are common examples.
CEFR	CEFR (Common European Framework of Reference for Languages) is the international scale for language proficiency, running from A1 (beginner) to C2 (mastery). You may recognise it from language courses and exams.
Citation	A citation is one event: one AI answer using one URL as a source.
Claim	A claim is one thing an AI assistant said about one brand in one answer - that its pricing is unclear, that it suits enterprise buyers, that its support is excellent.
CLS	CLS (Cumulative Layout Shift) measures how much a page's layout jumps unexpectedly while it loads - content sliding down when a late image or advert appears, buttons moving as you try to tap them. It is one of Google's Core Web Vitals.
CMS	A CMS (content management system) is the software used to create, edit and publish website content without writing code. WordPress, Drupal and Contentful are common examples.
Connector address	A link that tells an AI product where Silktide is. Not a password.
Contrast ratio	A contrast ratio measures how different two colours are in brightness, on a scale from 1:1 (identical colours) to 21:1 (black on white). Accessibility standards use it to judge whether text and controls stand out enough from their background - for example, WCAG requires body text to have a contrast ratio of at least 4.5:1 against its background.
Cookie	A cookie is a small piece of data a website stores in a visitor's browser, which the browser sends back with later requests. Cookies keep people signed in, remember preferences, and track behaviour. Attributes set alongside a cookie control how long it lasts and when the browser is allowed to send it.
Core Web Vitals	Core Web Vitals are Google's standard measurements of how a page feels to use. The three metrics are:
CORS	CORS (Cross-Origin Resource Sharing) is the browser mechanism that controls whether a web page may use files and data from a different domain than its own. The server hosting the file must explicitly permit other sites to use it via CORS HTTP headers, otherwise the browser blocks the request - a common cause of fonts and scripts failing to load.
Crawler	A crawler is a program that reads websites automatically by following links from page to page. Search engines use crawlers to build their indexes, AI assistants use them to read the web, and Silktide uses one to discover and test the pages of your website.
CSS	CSS (Cascading Style Sheets) is the language that controls how web pages look: colours, fonts, spacing, and layout. It works alongside HTML, which provides the content being styled.
Decision	A decision is your recorded judgement about a finding, made in the Inspector. Decisions come in two flavours with importantly different meanings:
Decorative image	A decorative image serves only an aesthetic purpose - it adds no information and has no function. Backgrounds, flourishes, and spacers are typical examples.
DOM	The DOM (Document Object Model) is the browser's internal model of a web page: every heading, paragraph, image, and container becomes a node in a tree the browser builds from the page's HTML.
Education tier	Education tier expresses text difficulty as the stage of schooling a reader would typically need to follow it comfortably: Primary, Lower secondary, Upper secondary, or Tertiary (university-level). The tiers follow the international ISCED classification of education levels.
EN 301 549	EN 301 549 ("Accessibility requirements for ICT products and services") is the European standard for digital accessibility. When EU law requires something digital to be accessible, this is the standard that defines what "accessible" means - regulations such as the EU Web Accessibility Directive, the European Accessibility Act, and the UK's PSBAR all point to it.
Engaged time	Engaged time is the time a visitor spent actively using a page: the tab in the foreground, and the visitor scrolling, clicking, typing or moving the pointer. It stops when the tab is hidden, and 10 seconds after the visitor last did something when the page is left untouched. It starts again when they come back.
Event listener	An event listener is JavaScript code that runs when something happens on a page, such as a click, a key press, or a touch. Pages register listeners for the events they care about; most interactive behaviour on the modern web is built this way.
Favicon	A favicon is the small icon a browser shows for a website in tabs, bookmarks and history, and which phones use when a site is saved to the home screen. Sites declare favicons with <link rel="icon"> tags in the page's HTML, or by placing a favicon.ico file at the site root; a site will often provide several sizes and formats so every device can pick the best fit.
GDPR	The GDPR (General Data Protection Regulation) is the European Union's data protection law. It governs how organisations collect, store and share personal data about people in the EU, requires a lawful basis such as explicit consent for processing, and carries significant fines for violations.
Glyph	A glyph is the drawn shape of a character: the specific marks a font puts on the page. The character is the meaning, the glyph is the picture of it.
HTML	HTML (HyperText Markup Language) is the language web pages are written in. It describes a page's content and structure - headings, paragraphs, links, images, forms - which the browser turns into what you see.
HTTP header	An HTTP header is a piece of information sent invisibly alongside a web page or other resource, as part of the request or response. Headers let browsers and servers exchange instructions - such as how long to cache a page, what type of content it is, or what security rules to apply - without changing anything visitors see.
HTTPS	HTTPS is the secure version of HTTP, the protocol browsers use to fetch web pages. The "S" means the connection is encrypted, so nobody between the visitor and the website can read or tamper with what is sent - including passwords and personal details.
INP	INP (Interaction to Next Paint) measures how quickly a page responds after someone taps, clicks, or presses a key - from the input until the next visual update. It is one of Google's Core Web Vitals.
Integration	An integration is a connection between Silktide and another product your team already uses, such as a task tracker or a chat tool. Once connected, Silktide can send work or alerts into that product instead of anyone copying them manually.
JavaScript	JavaScript is the programming language that makes web pages interactive: menus that open, content that loads without a refresh, forms that validate as you type. It runs in the visitor's browser, alongside the page's HTML structure and CSS styling.
JSON-LD	JSON-LD is the format most structured data is written in: a small block of machine-readable JSON embedded in a page's HTML, invisible to visitors, that describes what the page contains.
Keyboard focus	Keyboard focus marks the element on a page that currently receives keyboard input, usually shown with an outline. People who navigate without a mouse move focus between links, buttons, and form fields using keys such as Tab, so every interactive element must be reachable and usable via focus.
Label	A label is a reusable marker you apply to websites, sections, or documents so you can group and filter them. Typical labels name a business unit, region, owner, or lifecycle stage.
Last-Modified	Last-Modified is an HTTP header a web server can send alongside a page or a file, declaring when that content last changed. For example:
Lazy loading	Lazy loading means waiting to load a resource - an image, video, script, or widget - until it is actually needed, rather than loading everything when the page first loads. It makes the initial page load faster by using bandwidth and processing time only on what the visitor actually sees or uses.
LCP	LCP (Largest Contentful Paint) measures how long it takes for the main content of a page to appear - typically the largest image or text block in the viewport. It is one of Google's Core Web Vitals.
Live region	A live region is a part of a web page marked so that assistive technology announces changes to it automatically, without the user moving focus. Live regions are created with ARIA attributes such as aria-live, role=\"alert\", and role=\"status\", and are the standard way to announce dynamic updates such as form error messages.
llms.txt	llms.txt is a proposed convention: a Markdown file at the root of a website (for example https://example.com/llms.txt) that gives AI assistants a concise, curated summary of the site — what it is and links to its most important content.
Machine-readable text	Machine-readable text is real characters that software can select, search, and announce - not a picture of letters.
Main thread	The main thread is the single lane of work where a browser builds the page, runs most JavaScript, and responds to clicks, taps and scrolling. Only one task can run on it at a time, so while a long task runs, the page appears frozen. Performance advice often focuses on keeping the main thread free.
Market	A market groups the topics that compete in one space inside a workspace. Every workspace has at least one - created with the workspace and named for what you compete in - and every topic belongs to exactly one. Brand topics sit outside markets, because a brand is not a competitive space.
Matterhorn Protocol	The Matterhorn Protocol is the PDF Association's testing model for PDF/UA. It turns the formal standard into 31 checkpoints and 136 failure conditions that tools and human auditors can apply the same way.
MCP	A way for ChatGPT, Claude, and Cursor to use your Silktide account.
Mention	A mention is a brand being named in an AI assistant's answer.
Meta description	A meta description is a short summary of a page, written in an invisible HTML tag in the page's header:
Minification	Minification rewrites code files - JavaScript, CSS or HTML - so that they are as small as possible without changing their behaviour, by stripping comments, whitespace and other characters that only matter to people reading the code. Smaller files download more quickly, so minification is a standard, fully automated step when preparing a website for production.
Noindex	Noindex is an instruction that tells search engines not to include a page in their search results. It is set with a robots meta tag in the page's HTML, or with an X-Robots-Tag response header:
OCR	OCR (optical character recognition) is technology that converts images of text - such as scanned pages - into real, machine-readable text that can be selected, searched, and read aloud by a screen reader.
Open Graph	Open Graph is a set of tags added to a page's HTML that describe how the page should be presented when it is shared — typically a title, description, image and link. Social networks and messaging apps such as Facebook, LinkedIn, Slack and Teams read these tags to build the preview card people see.
Page allowance	A page allowance is the maximum number of pages a website may use from your account's available capacity, reserved in the website's settings. When a site has more pages than its allowance, testing stops once the allowance is reached, so some pages go untested - the coverage reports show where. An allowance limits how much content is retained; it does not expand what is in scope to test.
PDF\/UA	PDF\/UA (PDF\/Universal Accessibility, ISO 14289) is the international standard for accessible PDF documents. The version Silktide validates against is PDF\/UA-1.
Personal data	Personal data is any information that identifies, or could identify, a living person - a name, a personal email address or telephone number, a photo, or an online identifier. Privacy laws such as the GDPR restrict how personal data may be collected, published and stored.
Prompt	In Presence, a prompt is one question inside a topic that Silktide asks AI assistants - phrased the way a real person would ask.
Rate limiting	Rate limiting is a server deliberately refusing requests because they are arriving too quickly. Rather than slowing down, most servers reject the extra requests outright and answer with the HTTP status code 429 Too Many Requests.
Reading age	Reading age expresses how difficult a piece of text is as the age at which a typical reader could comfortably follow it. A reading age of 13 means an average 13-year-old could read it comfortably - and so can everyone older, which is the point.
Reading order	Reading order is the sequence assistive technology follows through a page or PDF — not necessarily the order things look arranged on-screen.
Response	A response is one AI assistant's answer to one prompt at one moment, stored word for word.
Responsive design	Responsive design is an approach to building web pages so their layout adapts to the size of the screen, from wide desktop monitors to narrow phones. A responsive page rearranges and resizes its content with flexible layouts and CSS rules instead of serving a separate mobile site.
robots.txt	robots.txt is a plain text file at the root of a website (for example https:\/\/example.com\/robots.txt) that tells automated crawlers which parts of the site they may fetch.
Role map	A role map tells a PDF reader what a custom tag means, by pointing it at one of the standard structure types the format defines.
sameAs	sameAs is a property in structured data that links a person or organisation mentioned on a page to their official profiles elsewhere - for example a company's Wikipedia page, LinkedIn profile, or verified social media accounts.
Screen reader	A screen reader is software that reads a page aloud (or renders it as braille) for people who are blind or have low vision. JAWS, NVDA, and VoiceOver are common examples.
Section	A section is a defined part of a website that Silktide reports on as if it were a site of its own, with its own scores, results, and settings where needed.
SEO	SEO (Search Engine Optimisation) is the practice of making a website easier for search engines to find, understand, and rank - so the right pages appear when people search.
Share of voice	Share of voice is how much of the conversation is yours: of all the brand mentions counted in scope, the proportion that were you.
Social proof	Social proof is evidence that other people already trust a product or organisation: customer testimonials, reviews and ratings, recognisable customer logos, case studies, usage numbers ("trusted by 10,000 teams"), awards, and certifications.
Strategy brief	A strategy brief is an AI-written plan for improving how assistants talk about your brand, argued from your own measurements rather than from general advice.
Structure tree	The structure tree is where a tagged PDF keeps its tags: a single hierarchy, from the document down through sections, headings, paragraphs, lists, tables, and figures, describing what every piece of content is and what it belongs to.
Structured data	Structured data is machine-readable metadata embedded in a web page that describes what the page contains - for example that it is an article, who wrote it, and when it was published. It is usually written as JSON-LD using the schema.org vocabulary:
Subprocessor	A subprocessor is another organisation that handles personal data on your behalf, under a written contract. In Silktide, each AI provider you enable is a subprocessor: Silktide is already processing your account's data, and that provider receives what it needs so the AI can complete the work.
Success criterion	A success criterion is one individual, testable requirement in WCAG - the numbered statements the whole standard is made of, such as 1.1.1 Non-text Content ("all non-text content has a text alternative") or 1.4.3 Contrast (Minimum) ("text has a contrast ratio of at least 4.5:1").
Tagged PDF	A tagged PDF contains a hidden layer of structure - tags - that tells assistive technology what each piece of content is and in what order to read it: this is a level-two heading, this is a list of four items, this table cell belongs to that column header, this image means X, this flourish is decorative and should be skipped.
Topic	A topic is an arena where you want AI visibility: a subject area including its qualifier (for example "undergraduate nursing programmes" or "smartphones"), not a vague one-word label.
Trait	A trait is a recurring quality that AI assistants attach to brands - "opaque pricing", "built for developer workflows", "strong accessibility expertise" - with every claim that fits it grouped underneath.
Transcript	A transcript is a text document containing everything said in a piece of audio or video, and often descriptions of meaningful sounds and visuals too. Unlike captions, a transcript is not synchronised with playback - it is read as ordinary text.
Unicode	Unicode is the universal standard that gives every character in every writing system its own number, so that software can agree on what a piece of text says.
Viewport	The viewport is the visible area of a web page inside the browser window. On mobile devices, pages control how they scale to the screen with a <meta name="viewport"> tag, which sets the page width and zoom behaviour - including, undesirably, the ability to prevent users from zooming.
Visit duration	Visit duration is how long a visitor spent actively using the website during a visit: their engaged time on each page, added up across the pages of the visit. The Overview's Duration chart averages it across the visits in the period, the Pages report shows the average for a view of each page, and on the Journeys screen it is the Duration column.
WCAG	WCAG (Web Content Accessibility Guidelines) is the international standard for making web content usable by people with disabilities. It is published by the W3C (World Wide Web Consortium) and is the basis of most accessibility law and policy worldwide - and the standard that most of Silktide's accessibility checks test against.
WCAG levels (A, AA, AAA)	---\ntype: definition\nnavHidden: true\ntitle: WCAG levels (A, AA, AAA)\ncreated: 2026-07-16T02:20:00Z\nupdated: 2026-08-26T04:53:33Z\n---\n\n# WCAG levels (A, AA, AAA)\n\nEvery WCAG success criterion has a conformance level that indicates how essential it is:\n\n- Level A - the minimum. Failing these makes content unusable for some people.\n- Level AA - the widely required standard. Most laws, regulations, and contracts that reference WCAG require Level AA, which includes everything in Level A.\n- Level AAA - the strictest level. Valuable where achievable, but not expected across an entire website.\n\nWhen someone says a website must "meet WCAG 2.2 AA", they mean it should satisfy every Level A and Level AA criterion in WCAG version 2.2. Silktide allows you to filter accessibility results by level so you can focus on the standard that applies to you.\n\n## Learn more\n\n- Understanding Conformance - how the W3C defines levels and conformance\n- WCAG\n
Website (in Silktide)	In Silktide, a website is a thing you test: a set of URL rules that determine which pages belong to it. Most often, that is simply everything on a single hostname, such as example.com, but the rules can be as specific as you need - for example everything on example.com except the pages under /private/.
Workspace	A workspace is where a brand competes: a named set of topics - the demand space, such as "Website governance" or "UK business banking" - plus the identity brand whose workspace it is.
XML sitemap	An XML sitemap is a machine-readable file, usually at /sitemap.xml, that lists the pages of a website you want search engines to crawl and index. Large sites often split it into several files, joined by a sitemap index.
XMP metadata	XMP is the standard format PDFs and other files use to carry metadata about themselves: the document title, author, language, copyright, and any conformance claims the file makes.