Glossary
What the terms on this site mean
Accessibility work comes with a lot of jargon. Here is what each term means, in plain words.
Conformance levels in an Accessibility Conformance Report (ACR)
In an ACR, each Web Content Accessibility Guidelines (WCAG) criterion gets one of these ratings. The definitions are the official wording from the Information Technology Industry Council's Voluntary Product Accessibility Template (VPAT), version 2.5.
- Supports
- The functionality of the product has at least one method that meets the criterion without known defects or meets with equivalent facilitation.
- Partially Supports
- Some functionality of the product does not meet the criterion.
- Does Not Support
- The majority of product functionality does not meet the criterion.
- Not Applicable
- The criterion is not relevant to the product.
- Not Evaluated
- The product has not been evaluated against the criterion. This can only be used in WCAG Level AAA criteria.
Terms, A to Z
- Accessibility Conformance Report (ACR)
- A completed VPAT: a report that says, criterion by criterion, how well a product meets an accessibility standard, with a remark explaining each rating.
- Americans with Disabilities Act (ADA), Title II
- The U.S. civil rights law for people with disabilities. Title II covers state and local governments, and its 2024 rule requires their websites and apps to meet WCAG 2.1 Level AA.
- Assistive technology
- Software or hardware people use to work with a computer or phone, such as a screen reader, voice control or a screen magnifier.
- CAPTCHA
- A test meant to prove you are a person, such as typing distorted letters or picking pictures. Many disabled people find them hard or impossible, so our form doesn't use one.
- Success criterion
- One testable requirement in WCAG, such as 1.4.3 Contrast (Minimum). WCAG 2.2 has 86 of them. Plural: criteria.
- DHS Trusted Tester
- A certification from the U.S. Department of Homeland Security (DHS) for people who test against Section 508 using its standard method.
- EN 301 549
- The European accessibility standard for digital products and services. Its web requirements match WCAG. It is used in European Union (EU) public procurement and the European Accessibility Act.
- User flow (task)
- A complete task someone does in a product from start to finish, such as signing in or submitting an application. We test whole flows, not just single pages.
- House Bill 21-1110 (HB21-1110)
- Colorado's digital accessibility law for state agencies, local governments, school districts and special districts. It has applied since July 1, 2025.
- JAWS (Job Access With Speech)
- A paid screen reader for Windows, widely used at work.
- Level A, AA and AAA
- The three levels of WCAG criteria. Level A is the minimum, AA is what most laws and contracts require, and AAA is the highest.
- Non-disclosure agreement (NDA)
- A contract that keeps shared information confidential.
- NVDA (NonVisual Desktop Access)
- A free, open-source screen reader for Windows.
- Accessibility overlay
- A script added to a website that claims to fix accessibility automatically. Overlays don't fix the underlying code, and many disabled people find them harder to use.
- PDF/UA
- The standard for accessible PDF files (ISO 14289). A PDF/UA file is tagged so screen readers can read its headings, tables and links in order.
- Remediation
- Fixing the accessibility problems an audit found.
- Request for proposal (RFP)
- A buyer's formal request for bids. Many public-sector RFPs ask vendors for a current ACR.
- Screen reader
- Software that reads the screen aloud or sends it to a braille display, so people who are blind or have low vision can use a computer or phone. Examples: NVDA, JAWS, VoiceOver and TalkBack.
- Section 508
- Part of the U.S. Rehabilitation Act. It requires federal agencies to buy and build accessible technology, and uses WCAG for web content.
- Severity
- How much a problem gets in people's way: Critical, High, Medium, Low or Advisory. See How we test.
- TalkBack and VoiceOver
- The screen readers built into Android (TalkBack) and Apple devices (VoiceOver).
- Voluntary Product Accessibility Template (VPAT)
- The blank template, from the Information Technology Industry Council (ITI), that a vendor fills in to create an ACR. It comes in four editions: WCAG, Section 508, European Union (EU) and International (INT), which covers all three. There is no official VPAT certification.
- World Wide Web Consortium (W3C)
- The organization that publishes web standards, including WCAG.
- Web Content Accessibility Guidelines (WCAG)
- The international standard for accessible websites, apps and documents, published by the W3C. Versions 2.0, 2.1 and 2.2 are in use; laws and contracts name the version they require.
- WCAG-EM
- The W3C's method for evaluating a whole website against WCAG: define the scope, choose a representative sample, test it and report.