Here’s the definition from the Web Accessibility Initiative on the W3C (World Wide Web Consortium) website:
“Web accessibility means that people with disabilities can perceive, understand, navigate, and interact with the Web, and that they can contribute to the Web.”
Rachel Cherry, a Senior Software Engineer for The Walt Disney Company says, “Web accessibility refers to the inclusive practice of removing barriers that prevent interaction with, or access to, websites by people with disabilities.”
Websites can be designed to be accessible by people with disabilities. Those with visual, audio, and physical disabilities can and should be able to access your website.