Glossary

Searchable terminology from accessibility, web standards, and related fields.

6 results found in visual design.

CSS Box Model (Box Model)
A fundamental concept in CSS that describes how HTML elements are rendered as rectangular boxes with four distinct areas: content (the actual text or image), padding (space between content and border)…
Color Contrast (Colour Contrast, Contrast Ratio)
The difference in luminance between foreground text (or UI components) and their background, measured as a ratio. WCAG 2.1 requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large …
Editorial Enunciation (Visual Enunciation)
A semiotic concept describing how the visual layout and organisation of an interface communicates meaning beyond the content it contains. Editorial enunciation encompasses the spatial arrangement, siz…
Legibility
The visual clarity with which individual characters, words, and blocks of text can be distinguished and recognised. Legibility is influenced by font choice (sans-serif fonts are generally more legible…
Luminance (Relative Luminance)
The relative brightness of a color as perceived by the human eye, measured on a scale from 0 (black) to 1 (white). In accessibility, relative luminance is the foundation of WCAG color contrast ratio c…
Tiresias (Tiresias Screenfont, Tiresias Font Family)
A family of typefaces developed in 1998 by the Royal National Institute of Blind People (RNIB) specifically designed for legibility on screen displays, particularly television subtitling. Named after …