Biscotti are Italian almond biscuits (cookies) that originated in the city of Prato. They are twice-baked, oblong-shaped, dry, and crunchy (Wikipedia, nd).
Biscotti are made with a number of ingredients, including flour and flavorings. Recipes for biscotti can change, and can add new ingredients, so check the ingredients of the biscotti carefully before consumption. In the event of an allergic reaction after having biscotti, contact your allergist.
Since they are very dry, biscotti traditionally are served with a drink, into which they may be dunked, or alone as a desert (Wikipedia, nd).