Purpose
Canonical definitions for accessibility engineering terminology. Every term should have one clear meaning across all framework documents.
Glossary
Accessibility
The design of products, devices, services or environments for people with disabilities. In software engineering, accessibility ensures that digital products can be used by people with diverse abilities.
Alternative Text (Alt Text)
A text alternative for non-text content such as images. Alt text is read by screen readers and displayed when images do not load. It should convey the purpose and content of the image.
ARIA (Accessible Rich Internet Applications)
A W3C specification that provides attributes to enhance the accessibility of dynamic content and custom user interface widgets. ARIA supplements HTML semantics but should not be used as a substitute for semantic HTML when native elements are available.
Assistive Technology (AT)
Tools used by people with disabilities to interact with digital content. Examples include screen readers (JAWS, NVDA, VoiceOver), screen magnifiers, speech recognition software and switch devices.
Colour Contrast
The difference in luminance between foreground text and its background. Sufficient contrast is essential for readability. WCAG requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (Level AA).
Focus Indicator
A visual cue that shows which element on the page currently has keyboard focus. Custom focus indicators should have sufficient contrast and not be removed unless a replacement is provided.
Keyboard Accessibility
The ability to navigate and operate all functionality using a keyboard alone. Keyboard accessibility is a fundamental requirement for users with motor disabilities and screen reader users.
Landmark
An ARIA role or HTML element that identifies the major regions of a page (navigation, main, complementary, contentinfo). Landmarks enable screen reader users to navigate quickly between sections.
Screen Reader
An assistive technology that reads digital content aloud. Users rely on semantic HTML, ARIA attributes and keyboard navigation to understand and interact with content.
Semantic HTML
The use of HTML elements according to their intended meaning rather than their visual appearance. Semantic HTML provides built-in accessibility support and is the foundation of accessible web development.
Skip Link
A link at the top of a page that allows keyboard and screen reader users to skip directly to the main content, bypassing repeated navigation elements.
WCAG (Web Content Accessibility Guidelines)
The international standard for web accessibility published by the W3C. WCAG is organised around four principles: Perceivable, Operable, Understandable and Robust (POUR).
WAI-ARIA Authoring Practices
A W3C guide that provides recommendations for making advanced user interface patterns accessible. It covers patterns for menus, dialogs, tabs, carousels and other common widgets.