Accessibility terms, made clear

Accessibility audit

The evaluation of a site against accessibility criteria. It combines automated tests and manual review.

Accessibility overlay

A widget added in one line of code that claims to make a site compliant. It does not fix the source code and is increasingly contested.

Accessibility statement

A public document stating a site's conformance level, non-accessible content and a contact channel. Often mandatory.

Assistive technology

Any tool that helps a person with a disability use digital products: screen reader, magnifier, switch device, voice recognition.

Audio description

An audio track that describes the important visual elements of a video, for blind or visually impaired people.

Captions

The synchronised text of a video, essential for deaf or hard-of-hearing people and useful to all.

Colour contrast

The brightness ratio between text and its background. Sufficient contrast is required for readability (a very common WCAG criterion).

Digital accessibility

Designing websites, apps and documents usable by everyone, including people with disabilities.

Directive 2016/2102 (public sector)

The European directive on the accessibility of public sector websites and apps, predating the EAA.

EN 301 549

The harmonised European standard defining accessibility requirements for ICT products and services. For the web, it builds on WCAG level AA.

European Accessibility Act (EAA)

European directive (EU) 2019/882 that requires many digital products and services sold to EU consumers to be accessible, applicable since 28 June 2025.

Keyboard navigation

The ability to use a whole site without a mouse, with the keyboard alone. Essential for many people with disabilities.

Level AA

The WCAG conformance level targeted by most legal obligations, including the EAA. It covers level A and AA criteria.

POUR (perceivable, operable, understandable, robust)

The four founding principles of WCAG. All accessible content must be perceivable, operable, understandable and robust.

Remediation

The set of fixes applied to a site to resolve the accessibility problems identified by an audit.

RGAA (French accessibility standard)

Référentiel Général d'Amélioration de l'Accessibilité: the French framework that operationalises WCAG with a detailed testing method.

Screen reader

Software that renders screen content as speech or braille, used in particular by blind or visually impaired people.

Success criterion

A testable WCAG requirement. Each criterion describes a verifiable condition, passed or failed, at level A, AA or AAA.

Text alternative (alt text)

The textual description of an image, read by assistive technologies when the image cannot be seen.

Visible focus

The visual indicator showing which element has keyboard focus. It must stay clearly perceptible.

VPAT / accessibility conformance report

A document detailing, criterion by criterion, the conformance level of a digital product. Often requested by buyers.

WAI-ARIA

A set of HTML attributes that describe the role and state of rich components to assistive technologies.

WCAG 2.2

Web Content Accessibility Guidelines: the international W3C standard defining how to make web content accessible. Version 2.2 is the current reference.