Concepts and terms from the world of accessibility

An international standard that defines guidelines for making web content accessible. WCAG is organized into three conformance levels: A, AA and AAA. Most regulations worldwide (including ADA practice and EN 301 549) require Level AA conformance.

The Level AA conformance level of WCAG 2.1, widely treated as the legal baseline for public-facing websites under the ADA, Section 508, EN 301 549 and most national accessibility laws. Israel's IS 5568 standard is also based on WCAG 2.0 AA.

A set of HTML attributes that add semantic information to complex UI components so that screen readers and other assistive technologies can interpret and communicate them to the user.

Software that converts on-screen content into speech or Braille output. Examples include NVDA (free, Windows), JAWS (Windows), VoiceOver (Apple) and TalkBack (Android). Screen readers are the primary tool blind users rely on to browse the web.

Text that describes an image, shown when the image fails to load and read aloud by screen readers. Required on every image that conveys information. Purely decorative images should use an empty alt="".

The contrast ratio between text color and its background. WCAG Level AA requires at least 4.5:1 for normal text and 3:1 for large text. Low contrast makes content hard to read for users with low vision.

The ability to browse and operate every function on a site using only a keyboard (Tab, Enter, arrow keys, Escape). Essential for users who cannot use a mouse, including many motor-impaired and blind users.

A document published on a website that describes its accessibility level, the adjustments made, and contact details for reporting accessibility issues. Required by law in many jurisdictions, including Israel and the EU.

A software tool installed on a site that lets users adjust their browsing experience — enlarging text, changing contrast, stopping animations and more. Widgets complement core accessibility work but do not replace it.

Using HTML elements according to the meaning of the content (e.g., header, nav, main, article, button) rather than only for visual styling. Semantic HTML lets assistive technologies understand the structure of the page.

A visual cue (usually an outline) showing which element currently has keyboard focus. Required by WCAG SC 2.4.7 — never remove the focus outline in CSS without providing a clear replacement.

A U.S. civil rights law that prohibits discrimination based on disability. Courts have repeatedly held that the ADA applies to public-facing websites, with WCAG 2.1 AA serving as the de-facto compliance benchmark. ADA non-compliance can lead to lawsuits and settlements.