Olives are classified as edible fruits, more precisely as drupes of the olive tree. This plant characterizes the rural landscape of the southern areas of Italy and more in general of the Mediterranean basin. This drupa has a typical oval shape and usually has the petiole on the top that held it to the tree. It is composed of three parts,: the first is called epicarp and is thin and almost transparent with the function of protecting the fruit from, for example, dehydration; the he second part is the mesocarp which corresponds to the pulp and the fuller part of the fruit; the third part is instead the endocarp which represents the kernel or "almond of olives". The difference between green olives and black olives lays in when they are harvested. The green ones are harvested prematurely and so need subsequent passages to make them more palatable- the method of soaking in brine is the most practiced and widespread.