Accessibility Glossary
Definitions of common terms used in digital accessibility — from standards and laws to certifications, tools, and core concepts.
A
- ADAStandards & Laws
- Americans with Disabilities Act. A US civil rights law (1990) that prohibits discrimination against people with disabilities in employment, public accommodations, and other areas. Title III requires places of public accommodation — including websites — to be accessible.
- AODAStandards & Laws
- Accessibility for Ontarians with Disabilities Act. Ontario, Canada legislation (2005) requiring public and private organizations to meet accessibility standards including WCAG 2.0 Level AA for websites and web content.
- ACRDocuments & Reports
- Accessibility Conformance Report. The document produced using a VPAT template to report how a product conforms to accessibility standards. ACRs are commonly requested by enterprise customers and government agencies during procurement.
- ARIATechnologies & Tools
- Accessible Rich Internet Applications. A W3C specification (WAI-ARIA) that defines a set of HTML attributes — roles, states, and properties — to make dynamic web content and custom UI components accessible to assistive technologies. Examples: role="dialog", aria-label, aria-expanded.
- ATTechnologies & Tools
- Assistive Technology. Any hardware or software that helps people with disabilities use computers and digital content. Common examples include screen readers, screen magnifiers, switch access devices, eye-tracking software, and refreshable braille displays.
- axeTechnologies & Tools
- An open-source accessibility testing engine developed by Deque Systems. Available as a browser extension, npm package, and integrated testing library. axe is widely used for automated accessibility audits and is the engine behind many commercial accessibility tools.
- Alt TextConcepts
- Alternative text (the alt attribute in HTML) is a short description of an image that conveys its meaning to users who cannot see it. Screen readers read alt text aloud. Decorative images should have an empty alt attribute (alt="") so screen readers skip them.
C
- CPACCRoles & Certifications
- Certified Professional in Accessibility Core Competencies. An entry-level certification from the International Association of Accessibility Professionals (IAAP) covering disability, accessibility, and universal design concepts. A good starting point for those new to the accessibility field.
- CPWARoles & Certifications
- Certified Professional in Web Accessibility. An advanced IAAP certification combining both CPACC knowledge and Web Accessibility Specialist (WAS) technical skills. Demonstrates expertise across both the conceptual and technical dimensions of web accessibility.
- Cognitive AccessibilityConcepts
- Design practices that make digital content usable for people with cognitive disabilities, including learning disabilities, ADHD, autism, and acquired brain injuries. This includes clear language, consistent layouts, predictable navigation, and reducing cognitive load.
- Color ContrastConcepts
- The ratio of luminance between foreground (text) and background colors. WCAG 2.x requires a minimum ratio of 4.5:1 for normal text and 3:1 for large text (18pt or 14pt bold) at Level AA. Tools like the WebAIM Contrast Checker can verify compliance.
D
- DHS Trusted TesterRoles & Certifications
- A certification program from the US Department of Homeland Security (DHS) that trains testers to evaluate Section 508 conformance using a standardized, repeatable testing process. Required for accessibility testing on many US federal contracts.
E
- EAAStandards & Laws
- European Accessibility Act. EU directive (2019) requiring products and services — including websites, apps, and e-commerce — to meet accessibility standards across member states by June 2025.
- EN 301 549Standards & Laws
- The European standard for ICT (Information and Communication Technology) accessibility. It references WCAG 2.1 for web content and sets requirements for software, hardware, and documentation. Compliance with EN 301 549 is required for public sector procurement in the EU.
F
- Focus ManagementConcepts
- The practice of programmatically controlling keyboard focus so it moves logically as users interact with a page. Critical in single-page applications and modal dialogs: when a dialog opens, focus should move into it; when it closes, focus should return to the trigger element.
G
- GPATDocuments & Reports
- Government Product Accessibility Template. An older US government version of the VPAT used before the ITI standardized the current VPAT 2.x format. Occasionally still referenced in legacy procurement contexts.
J
- JAWSTechnologies & Tools
- Job Access With Speech. A commercial screen reader for Windows developed by Freedom Scientific (now Vispero). JAWS is one of the most widely used screen readers in enterprise and government settings, making it a key platform for accessibility testing.
K
- Keyboard NavigationConcepts
- The ability to use a website or app using only a keyboard (typically Tab, Shift+Tab, Enter, Space, and arrow keys) without a mouse or touch input. All interactive elements must be reachable and operable via keyboard. This is essential for users with motor disabilities and power keyboard users.
L
- Low VisionConcepts
- A level of vision loss that cannot be fully corrected with glasses, contact lenses, or surgery. People with low vision may use screen magnification, high contrast modes, or large text settings. Accessibility for low vision includes scalable text, sufficient contrast, and reflow at high zoom levels.
M
- Motor AccessibilityConcepts
- Design considerations for users with limited mobility or dexterity — including those with conditions like cerebral palsy, multiple sclerosis, RSI, or limb differences. Key considerations: keyboard operability, large click targets, no time-limited interactions, and support for switch access and voice control.
N
- NVDATechnologies & Tools
- NonVisual Desktop Access. A free, open-source screen reader for Windows developed by NV Access. NVDA is one of the most popular screen readers globally and is commonly used alongside JAWS and VoiceOver in accessibility testing.
S
- Section 508Standards & Laws
- An amendment to the US Rehabilitation Act requiring federal agencies to make their electronic and information technology accessible to people with disabilities. The 2018 refresh aligned Section 508 requirements with WCAG 2.0 Level AA.
- Semantic HTMLConcepts
- Using HTML elements according to their intended meaning rather than just their visual appearance. For example, using <button> for clickable actions (not <div>), <h1>–<h6> for headings in logical order, <nav> for navigation, and <main> for primary content. Semantic HTML is the foundation of accessibility — it gives assistive technologies the information they need to convey a page's structure.
- Skip LinksConcepts
- Hidden navigation links (visible on keyboard focus) that allow keyboard and screen reader users to jump past repetitive content — typically the main navigation — directly to the main content area. A skip link is usually the first focusable element on the page.
T
- TalkBackTechnologies & Tools
- The built-in screen reader for Android devices, developed by Google. TalkBack is essential for testing the accessibility of Android apps and mobile web content.
V
- VPATDocuments & Reports
- Voluntary Product Accessibility Template. A document framework created by the Information Technology Industry Council (ITI) that vendors use to report how their products conform to accessibility standards such as WCAG, Section 508, and EN 301 549. Completing a VPAT produces an ACR (Accessibility Conformance Report).
- VoiceOverTechnologies & Tools
- Apple's built-in screen reader available on macOS, iOS, iPadOS, and tvOS. VoiceOver is the primary tool for testing accessibility on Apple devices and is heavily used by blind and low-vision users worldwide.
W
- WCAGStandards & Laws
- Web Content Accessibility Guidelines. Published by the W3C, WCAG is the internationally recognized standard for web accessibility. Organized around four principles (Perceivable, Operable, Understandable, Robust), it defines success criteria at three conformance levels: A, AA, and AAA. WCAG 2.1 is the current widely-adopted version; WCAG 2.2 was published in 2023.
- WASRoles & Certifications
- Web Accessibility Specialist. A technical certification from the IAAP for professionals who test, remediate, and implement accessible web content. Covers WCAG, ARIA, assistive technologies, and testing methodologies.