A man listening to an audio recording on his phone

The A to Z of website accessibility – A glossary of terms

Whether you’re a web developer, a content creator, or a business owner, understanding the terminology associated with website accessibility is crucial for creating an inclusive digital environment.

With this in mind, we’ve compiled this comprehensive glossary designed to provide a clearer understanding of the key concepts, technologies, and legal considerations in the field of web accessibility. This guide aims to not only inform but also to inspire more accessible web practices. From ‘Alt Text’ to ‘Z-Index in Layouts,’ each term is explained with its relevance to making the web more inclusive and approachable for everyone.


A – Accessibility, ADA, Alt Text, ARIA

  • Accessibility: The practice of making your website usable by as many people as possible, including those with disabilities.
  • ADA: The Americans with Disabilities Act (ADA) U.S. legislation that requires public websites to be accessible to people with disabilities.
  • Alt Text: Short for “alternative text,” it describes images to users who can’t see them, crucial for screen reader users.
  • ARIA (Accessible Rich Internet Applications): A set of attributes that make web content more accessible by helping screen readers interpret complex web elements and controls.

B – Breadcrumbs, Button Labels

  • Breadcrumbs: A navigational aid showing the user’s location in a website’s hierarchy, aiding in navigation and understanding of site structure.
  • Button Labels: Descriptive labels for buttons, vital for screen reader users to understand the function of each interactive element.

C – Contrast Ratio, Captions, CSS

  • Contrast Ratio: The difference in color and brightness between text and its background, important for readability by visually impaired users.
  • Captions: Text versions of spoken words and sounds in videos, essential for deaf or hard-of-hearing users.
  • CSS (Cascading Style Sheets): Used to create visually engaging and accessible web designs that can adapt to different screen sizes and preferences.

D – Descriptive Links, Dyslexia-Friendly Fonts

  • Descriptive Links: Links with text that clearly explains where they lead, helping screen reader users make informed decisions about where to navigate.
  • Dyslexia-Friendly Fonts: Fonts designed to be easily readable by users with dyslexia, with unique shapes and adequate spacing.

E – Error Identification, Explicit Form Labels

  • Error Identification: Clearly identifying and explaining errors in forms, helping users with cognitive disabilities to understand and correct them.
  • Explicit Form Labels: Labels that clearly define the purpose of form fields, essential for screen reader users and those with cognitive impairments.

F – Focus Indicators, Fluid Layouts

  • Focus Indicators: Visual cues that highlight the element currently focused on, like a button or link, crucial for keyboard navigation.
  • Fluid Layouts: Designs that adjust smoothly to different screen sizes, ensuring content remains accessible and legible on all devices.
Woman on wheelchair listening to an audiobook on her ipad

G – Graceful Degradation, Gestalt Principles

  • Graceful Degradation: Ensuring that if newer technologies fail, the basic content of a website is still accessible.
  • Gestalt Principles: Design principles that help users perceive content as organized and coherent, beneficial for cognitive accessibility.

H – HTML5, Headers

  • HTML5: The latest standard for HTML, providing new features that enhance accessibility, like semantic elements.
  • Headers: Used to structure content logically, aiding screen readers in understanding and navigating page content.

I – Inclusive Design, Input Assistance

  • Inclusive Design: Designing websites to be usable by all people, to the greatest extent possible, without adaptation.
  • Input Assistance: Providing help to users when they input data, crucial for those with cognitive and learning disabilities.

J – JAWS (Job Access With Speech), JavaScript Accessibility

  • JAWS: A widely used screen reader that allows visually impaired users to read and navigate web content.
  • JavaScript Accessibility: Ensuring that interactive features created with JavaScript are accessible to all users, including those using assistive technologies.

K – Keyboard Navigation, Kinesthetic Accessibility

  • Keyboard Navigation: Making all web functions operable via keyboard, essential for users with motor disabilities.
  • Kinesthetic Accessibility: Accessibility considerations for users who interact with technology using touch or movement.
Motor challenges make it hard for some peolple to use keyboards

L – Landmarks, Live Regions

  • Landmarks: ARIA landmarks that define areas of a page (like navigation or main content), helping screen reader users navigate more easily.
  • Live Regions: Areas of a page where content updates dynamically, and which are announced by screen readers when changes occur.

M – Media Queries, Modal Dialogs

  • Media Queries: CSS technique to create responsive designs that adapt to different devices and screen sizes.
  • Modal Dialogs: Pop-up elements that must be designed to be easily navigable and dismissible by all users, including those using screen readers or keyboards.

N – Navigation Consistency, Non-Text Content

  • Navigation Consistency: Keeping navigation elements consistent across a website, aiding users with cognitive disabilities.
  • Non-Text Content: Providing alternatives for non-text content, like images or videos, so that all information is accessible to users who cannot perceive them directly.

O – Operable, On-Screen Keyboard

  • Operable: The principle that all components and navigation on a website must be operable by all users.
  • On-Screen Keyboard: A virtual keyboard displayed on the screen, useful for users with motor disabilities who cannot use a traditional keyboard.

P – Perceivable, Progressive Enhancement

  • Perceivable: Ensuring that all users can perceive the content in some form, a key principle of WCAG.
  • Progressive Enhancement: A strategy for web design that emphasizes core webpage content first, then adds more advanced functionalities.
A woman teaching a young man braille

Q – Quick Navigation, Quality of Text

  • Quick Navigation: Features allowing users to navigate quickly to key areas of a site, such as skip-to-content links.
  • Quality of Text: Ensuring text content is clear, concise, and readable, beneficial for users with cognitive or learning disabilities.

R – Responsive Design, Readable

  • Responsive Design: Designing content to work seamlessly across various devices and screen sizes, crucial for accessibility.
  • Readable: Making text content easily understandable, a key aspect of web accessibility, especially for users with cognitive disabilities.

S – Screen Readers, Semantic HTML

  • Screen Readers: Software that reads aloud web content, used by people who are blind or have visual impairments.
  • Semantic HTML: HTML that introduces meaning to the web page rather than just presentation, helping screen readers and other assistive technologies understand and interpret the content.

T – Tab Index, Transcripts

  • Tab Index: The order in which elements are focused when using the Tab key, important for keyboard navigation.
  • Transcripts: Written versions of audio content, essential for deaf or hard-of-hearing users.

U – Usability, User Control

  • Usability: The ease with which a website can be used by as many people as possible.
  • User Control: Allowing users to control time-sensitive content updates, pause or stop moving content, and adjust settings as needed.
Visually impaired man using computer in a library

V – Visual Impairment, Voice Recognition

  • Visual Impairment: Considerations for users with various degrees of visual ability, including color blindness, low vision, and blindness.
  • Voice Recognition: Technology enabling users to control a website using voice commands, useful for users with motor or visual impairments.

W – WCAG (Web Content Accessibility Guidelines), WAI-ARIA

  • WCAG: A set of guidelines for making web content accessible to people with a wide range of disabilities.
  • WAI-ARIA (Web Accessibility Initiative – Accessible Rich Internet Applications): Technical specifications to make web content more accessible, particularly dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies.

X – XML (eXtensible Markup Language), XHTML

  • XML: A markup language used for encoding documents in a format that is both human-readable and machine-readable, often used in data representation and accessibility.
  • XHTML (eXtensible Hypertext Markup Language): A hybrid between HTML and XML, used to create web pages that are easier to read by screen readers and other assistive technologies.

Y – YouTube Accessibility, YUI (Yahoo! User Interface) Library

  • YouTube Accessibility: Refers to the accessibility features available on YouTube, such as automatic captioning and keyboard navigable interfaces.
  • YUI (Yahoo! User Interface) Library: A set of JavaScript utilities and controls for building richly interactive web applications, with a focus on accessibility features.

Z – Zoom Functionality, Z-Index in Layouts

  • Zoom Functionality: The ability for users to enlarge text and other content on the web page, essential for users with low vision.
  • Z-Index in Layouts: Refers to the way elements are stacked on the web page; proper management ensures that interactive elements are accessible and navigable.