Accessibility, in the context of web development, refers to the practice of making websites usable by as many people as possible. This includes people with disabilities who may interact with the web in different ways, as well as those with temporary impairments, such as a broken arm, and those with changing abilities due to aging.
Web accessibility encompasses all disabilities that can impact web use, including:
- Visual: This includes blindness, low vision, color-blindness.
- Motor/Mobility: This includes difficulty or inability to use the hands, including tremors, muscle slowness, loss of fine muscle control, etc., due to conditions like Parkinson's Disease, muscular dystrophy, cerebral palsy, stroke.
- Auditory: Deafness or hearing impairments, including individuals who are hard of hearing.
- Seizures: Photo epileptic seizures caused by visual strobe or flashing effects.
- Cognitive/Intellectual: Developmental disabilities, learning disabilities (dyslexia, dyscalculia, etc.), and cognitive disabilities of various origins, affecting memory, attention, developmental "maturity," problem-solving and logic skills, etc.
Web accessibility also benefits people without disabilities, such as:
- Older people with changing abilities due to aging
- People with "temporary disabilities" such as a broken arm or lost glasses
- People with "situational limitations" such as in bright sunlight or in an environment where they cannot listen to audio
- People using a slow Internet connection, or who have limited or expensive bandwidth
Web accessibility is essential for some and useful for all. 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
- contribute to the Web
Web accessibility encompasses all disabilities that affect access to the Web, including visual, auditory, physical, speech, cognitive, and neurological disabilities.
The web is fundamentally designed to work for all people, whatever their hardware, software, language, location, or ability. When the Web meets this goal, it is accessible to people with a diverse range of hearing, movement, sight, and cognitive ability.
Thus the impact of disability is radically changed on the Web because the Web removes barriers to communication and interaction that many people face in the physical world. However, when websites, applications, technologies, or tools are badly designed, they can create barriers that exclude people from using the Web.
Web accessibility is required by law in many situations. More importantly, it is a crucial aspect of good citizenship and social responsibility. It's important to note that making websites accessible doesn't have to be complex or expensive, and it will often improve the usability for all users.
Web Content Accessibility Guidelines (WCAG) is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of providing a single shared standard for web content accessibility that meets the needs of individuals, organizations, and governments internationally.
WCAG documents explain how to make web content more accessible to people with disabilities. Web "content" generally refers to the information in a web page or web application, including:
- natural information such as text, images, and sounds
- code or markup that defines structure, presentation, etc.
Web accessibility strategies, guidelines, and resources help make the Web accessible to people with disabilities. These can range from simple changes like making sure you have alt tags for images, to more complex tasks like creating closed captions for videos.
Accessibility is a key aspect of web development that ensures everyone, regardless of their physical or mental abilities, can use and benefit from the web. It's a broad and important topic that affects a significant portion of the population, and it's a responsibility of all web developers to ensure their sites are accessible.