Definition
Pictograms are full-colour images that display at a fixed size of 64px. Single-colour icons are in the icon suites.
Pictograms are PNG files due to their colour complexity.
Pictograms come in two modes: base and inverted.
Accessibility
When using pictograms in a design, use the correct code to describe or hide the asset from assistive technologies.
If the pictogram is purely decorative, then the alt tag should be left empty, and the appropriate aria tag should be used. Based on the use case, the correct markup varies; the Web Accessibility Initiative (WAI) guidelines provide further examples.
Assets