"XForms" is W3C's name for a specification of Web forms that can be used with a wide variety of platforms including desktop computers, hand helds, information appliances, and even paper. XForms started life as a subgroup of the HTML Working Group, but has now been spun off as an independent Activity.
Traditional HTML Web forms don't separate the purpose from the presentation of a form. XForms, in contrast, are comprised of separate sections that describe what the form does, and how the form looks. This allows for flexible presentation options, including classic XHTML forms, to be attached to an XML form definition