Web accessibility (known in other fields as inclusive design or universal design) is the degree to which a website is available to as many people as possible. Accessibility is most often used to describe how people with disabilities can access the web.
Universal Design (UD) is an approach to design that increases the potential for developing a better quality of life for a wide range of individuals. It is a design process that enables and empowers a diverse population by improving human performance, health and wellness, and social participation (Steinfeld and Maisel, 2012). It creates products, systems, and environments to be as usable as possible by as many people as possible regardless of age, ability or situation.