An interface is accessible when people with differing sensory, motor and cognitive abilities can perceive its information and operate its essential functions.

Accessibility is not one special mode for a separate group of users. The design should avoid making one ability the only path to meaning or action.

Important information should not be encoded only by color, sound, fine pointer movement or another single channel. Controls need labels or other perceivable names, and interaction should remain understandable when presentation is enlarged or adapted.

Timing can also exclude users. Short timeouts, rapidly disappearing messages or actions that require precise simultaneous movement can make an otherwise visible interface unusable.

Assistive technologies can transform or supplement presentation, but they need meaningful structure and state from the application rather than a purely visual arrangement of anonymous elements.

Inclusive design asks which abilities an interaction assumes and, where practical, provides equivalent ways to obtain the same information and perform the same task.