Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
Text can be rendered in a visual, oral or tactile way. Even by any combination of them. So text information can be presented and manipulated in whatever form best meets the user needs. For example, a blind person can understand a picture if her browsers reads aloud the text alternative. Or a deaf person can understand an audio file if there is a text alternative on the screen.