DAISY (Digital Accessible Information System) is a technical standard for digital audio books, periodicals and computerized text. DAISY is designed to be a complete audio substitute for print material and is specifically designed for use by people with "print disabilities," including blindness, impaired vision, and dyslexia. Based on MP3 and XML, the format has advanced features in addition to those of a traditional audio book. Users can search, place bookmarks, precisely navigate line by line, and regulate the speaking speed without distortion. DAISY also provides aurally accessible tables, references and additional information. As a result, DAISY allows visually impaired listeners to navigate something as complex as an encyclopedia or textbook, otherwise impossible using conventional audio recordings.
Source: Wikipedia (http://en.wikipedia.org/wiki/DAISY_Digital_Talking_Book)