Glossary of Accessibility Terms
Digital accessibility comes with a vocabulary all its own. Whether you're a content creator, developer, or designer, understanding the terminology will help you communicate more effectively and create more inclusive experiences.
This glossary provides plain-language definitions of common accessibility terms, with a focus on content creation and web publishing.
Note: You should consult your agency's general counsel with any questions in regard to interpretation of ADA requirements.
A–C
Alt Text (Alternative Text)
A brief description of an image, provided using the alt attribute, that screen readers use to convey meaning to users who can’t see the image.
ARIA (Accessible Rich Internet Applications)
A set of HTML attributes that help make dynamic web content (like modals, tabs, or sliders) accessible to screen readers. Used only when semantic HTML isn’t sufficient.
Assistive Technology (AT)
Devices or software that help people with disabilities interact with digital content—includes screen readers, screen magnifiers, braille displays, voice input tools, etc.
Captions
Text that appears on video to represent spoken dialogue, sound effects, and speaker identification. Essential for users who are deaf or hard of hearing.
Cognitive Disabilities
Neurological or mental conditions that affect how someone processes information. Examples include ADHD, autism, and dyslexia.
Color Contrast
The difference in brightness between foreground (like text) and background. Adequate contrast ensures readability, especially for users with low vision.
D–H
Decorative Images
Images that don’t add meaningful content and can be safely hidden from screen readers using alt="" .
Descriptive Link Text
Hyperlink text that clearly describes the destination or action, rather than vague terms like “click here.”
Form Labels
Text that describes what input is expected in a form field. Screen readers rely on proper label associations to announce fields correctly.
Headings (H1–H6)
HTML tags that define the structure of content on a page. Used semantically to help users understand hierarchy and navigate more easily.
Hearing Impairments
Partial or total inability to hear. Affects the way users engage with audio content, making captions or transcripts necessary.
K–P
Keyboard Navigation
Using only the keyboard (no mouse or touchscreen) to navigate a website. Essential for users with motor disabilities or screen reader users.
Landmark Regions
Sections of a page defined by semantic HTML elements like <nav> , <main> , or <footer> . Assistive tech users can jump to these quickly.
Logical Reading Order
The sequence in which content is read aloud by assistive technology. It must match the visual and intuitive flow of the page.
Motor Disabilities
Conditions that affect a person’s physical ability to interact with a site—may require keyboard-only use or voice control.
PDF Accessibility
Ensuring PDF documents are structured with tags, reading order, alt text, and accessible form fields so they work with assistive tech.
POUR Principles
Four foundational principles of web accessibility:
- Perceivable – content must be available to the senses
- Operable – users can navigate and interact
- Understandable – content and interface behave predictably
- Robust – content works across technologies, including assistive tools
S–Z
Screen Reader
Software that converts text on the screen into speech or braille output. Common tools include JAWS, NVDA (Windows), and VoiceOver (macOS/iOS).
Semantic HTML
Using HTML elements according to their meaning, not just for styling. Examples: using <h2> for subheadings, <ul> for lists, <button> for actions.
Skip Link
A hidden link at the top of the page that allows keyboard users to skip directly to the main content, bypassing repeated navigation.
Tab Order
The order in which users move through elements on a page when pressing the Tab key. It should follow a logical, intuitive flow.
Transcript
A full-text version of spoken audio content, often used alongside podcasts or video. Helps users who are deaf, hard of hearing, or prefer to read.
WCAG (Web Content Accessibility Guidelines)
The global standard for digital accessibility, developed by the W3C. Organized into principles, guidelines, and success criteria at levels A, AA, and AAA.
Need More?
For a complete reference, visit:
🔗 W3C Accessibility Glossary
🔗 WebAIM Glossary