The ALT attribute also called as ALT tag are employed in XHTML and HTML documents in context of defining alternative text that is supposed to be rendered when the element can't be rendered to which it is applied. One great feature of ALT tag is that it is readable to 'screen reader' which is a software by means of which a blind person can hear this. In addition, it delivers alternative information for an image due to some specific reason a user can't view it, such as in case of a slow connection and an error occurred in the source attribute.