Accessibility Glossary

Definitions and practical explanations for web accessibility, testing workflows, alt text, PDF accessibility, digital accessibility, and UX signals.

Terms

• Accessible Authentication

  Accessible authentication means login, verification, and account recovery should not rely only on memory, image recognition, complex puzzles, or difficult interaction steps. It is one of the WCAG 2.2 success criteria most directly tied to real user tasks.

  
  
• Target Size

  Target size concerns whether buttons, links, and interactive controls have enough operable area so people can activate them without missed taps or accidental activation. WCAG 2.2 adds a success criterion for minimum target size.

  
  
• VPAT / ACR

  A VPAT is a template for producing an Accessibility Conformance Report, often used in procurement and vendor communication. It documents accessibility conformance status; it is not automatic certification or a complete user-experience guarantee.

  
  
• WCAG

  WCAG is the most widely used international guidance for evaluating web accessibility. Learn what WCAG A, AA, and AAA mean, how WCAG 2.1 and 2.2 differ, and how teams can check common issues across product, design, QA, and engineering workflows.

  
  
• Web Accessibility

  Web accessibility is the practice of making websites usable by people with different abilities, devices, and situations. Learn how it relates to WCAG, assistive technologies, user experience, and practical product work.

  
  
• ARIA

  ARIA is a set of roles, states, and properties that help assistive technologies understand complex or custom interactive components. Learn when to use ARIA and when native HTML is better.

  
  
• Keyboard Accessibility

  Keyboard accessibility means users can complete core tasks with Tab, Shift + Tab, Enter, Space, and arrow keys without relying on a mouse.

  
  
• Color Contrast

  Color contrast affects whether text, buttons, errors, and UI states are readable. It is one of the most common WCAG AA checks.

  
  
• Focus Indicator

  A focus indicator shows keyboard users where they are. If focus styles are removed or weak, users can get lost.

  
  
• Accessible Name

  An accessible name is the name assistive technologies use to identify buttons, links, form fields, and interactive controls.

  
  
• Screen Reader

  Screen readers use the accessibility tree to announce content, roles, states, and names so users can navigate and operate websites.

  
  
• Accessibility Overlay

  An accessibility overlay is usually a third-party script or widget added to a website to claim quick accessibility improvements. It cannot replace semantic HTML, design fixes, content work, manual testing, and real user feedback.

  
  
• Accessibility Statement

  An accessibility statement is a public page that explains a website or digital service’s accessibility status, applied standard, known limitations, improvement work, and feedback channels. It is not a certification or a compliance guarantee, but it helps users understand how barriers can be reported and followed up.

  
  
• Automated vs Manual Accessibility Testing

  Automated accessibility testing can quickly surface some WCAG and best-practice issues, while manual testing is still needed for content meaning, task flow, keyboard use, and assistive technology context.

  
  
• Alt Text

  Alt text communicates necessary information when an image cannot be seen or loaded. Good alt text depends on the image’s purpose in context, not only what appears in the picture.

  
  
• PDF Accessibility

  PDF accessibility concerns whether a document has language, tags, heading structure, bookmarks, links, image alternatives, and form information that assistive technologies can understand.

  
  
• Semantic HTML

  Semantic HTML uses the correct elements for structure and behavior so browsers, assistive technologies, and search engines can understand the page.