Most people today can hardly conceive of life without the internet. Some have argued that no other single invention has been more revolutionary since Gutenberg's printing press in the 1400s. Now, at the click of a mouse, the world can be "at your fingertips"—that is, if you can use a mouse... and see the screen... and hear the audio—in other words, if you don't have a disability of any kind.
This introduction should help you understand how people with disabilities use the web, the frustrations they feel when they cannot access the web, and what you can do to make your sites more accessible.