What does "perceivable" mean in web accessibility?

In the context of web accessibility, "perceivable" refers specifically to the idea that information and user interface components must be made available to users in a way that they can perceive them. This means that any content provided on a website must be accessible to all users, including those with disabilities.

For instance, text must be readable (with appropriate contrast), images should have alternative text descriptions for screen readers, and videos should offer captions or transcripts. The key aspect is that information should be presented in formats that are accessible—this includes considering visual, auditory, and tactile means of perceiving content.

While the other options touch on important aspects of web design, they do not directly relate to the concept of "perceivable." The focus on operability is more aligned with how users interact with content, while robust technologies and ease of navigation address different facets of web accessibility that complement, but do not encompass, the requirement for content to be perceivable.