Web accessibility describes the extent to which websites, tools, and technologies are accessible to individuals with disabilities who may rely on keyboard-only navigation, screen readers, closed captions, and other avenues for consuming information. Ideally, all web technologies will be accessible to people despite auditory, cognitive, neurological, speech, physical, or visual disabilities.
- Perceivability: Information must be presented in a way that users can perceive. For instance, a blind person will need an alternative description of an image on a webpage because they cannot take this information in visually.
- Operability: Users must be able to operate a particular web interface. For instance, someone with hand tremors or limited mobility should be able to use their keyboard to navigate through a website, select links, and fill out forms.
- Understandability: Web content should be understandable to users. For example, complex information should be stated without use of jargon and unclear wording.
- Robustness: Web content should be robust enough that it can be accessed with a range of technologies that may change or evolve over the course of time. For instance, an ebook should be accessible via various web browsers or screen readers, not just one.