What is the difference between sorbet and sherbet
Actually, they are not quite the same.  Sorbet is ice sweetened with fruit, wine, or liquer.  Italian ice, which is similar, does not contain ice but contains frozen fruit purees or similar.  Sherbert contains a small amount of dairy, but the milkfat content is less than 3%, differentiating it from ice cream.  

In the U. S. what is commonly called sorbet is most likely an Italian ice.  The difference is the lower milk fat content.