Definition and Meaning of Web Accessibility
Definition: Web accessibility means that the websites, tools, and technologies are designed and developed so that people with disabilities can use them. More specifically, people with disabilities should be able to perceive, understand, navigate, interact and contribute to the World Wide Web, also known as the Internet. (Source: W3C)
There are various types of disabilities and they pose different types of barriers to persons affected with disabilities. The term accessibility, or ability to access, refers to designing barrierless human environment so that everyone can use it.
Information barriers refer to the obstacles in accessing public information. Web accessibility, part of information accessibility, focuses on designing websites that are easily accessible to all the people, including people with disabilities.
Web accessibility aims to ensure information access for all people, including those with:
- Visual impairments including blindness, low vision and poor eyesight, color blindness etc.
- Locomotor disabilities. For example, difficulty in using the hands due to conditions such as Parkinson's disease, muscular dystrophy, cerebral palsy, stroke etc.
- Deafness or hearing impairments, including individuals who are hard of hearing;
- Epileptic seizures caused by visual strobe or flashing effects.
- Developmental disabilities, learning disabilities (dyslexia, dyscalculia, etc.), and cognitive disabilities (PTSD, Alzheimer's disease) etc.
However, web accessibility does not only address issues posed by various disabilities. It also aims to ensure information access in areas where network speed is slow. Thus, building light-weight and fast websites / apps also come under the purview of web accessibility.
Assistive technologies / devices play a significant role in implementing web accessibility. For example text-to-speech engines and refreshable Braille display, help people with visual impairment in accessing the content of a website.
WCAG guidelines propose four main principles to implement web accessibility.