Understanding Web Accessibility
Web accessibility means that websites, tools, and technologies are designed and developed so that people with disabilities can use them. More specifically, people can perceive, understand, navigate, and interact with the Web, and they can contribute to the Web.
Accessibility encompasses all disabilities that affect access to the Web, including auditory, cognitive, neurological, physical, speech, and visual disabilities. Accessibility also benefits people without disabilities, such as older people with changing abilities due to aging, people with temporary disabilities like a broken arm, and people with situational limitations such as bright sunlight or in an environment where they cannot listen to audio.
Key Principles of Accessibility
The Web Content Accessibility Guidelines (WCAG) are organized around four principles, often called by the acronym POUR:
- Perceivable: Information and user interface components must be presentable to users in ways they can perceive. This means that users must be able to perceive the information being presented (it can't be invisible to all of their senses).
- Operable: User interface components and navigation must be operable. This means that users must be able to operate the interface (the interface cannot require interaction that a user cannot perform).
- Understandable: Information and the operation of user interface must be understandable. This means that users must be able to understand the information as well as the operation of the user interface.
- Robust: Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.