Sorbet, sherbet, custard, gelato and soft serve are all different types of ice creams. The main difference is in the ingredients.
Custard, also known as French style, is a richer form of ice cream. It has a thicker texture since egg yolks are added into the mixture. Soft serve ice cream is similar to regular ice cream but it is not as cold. Also, soft serve has more air added to it, making it lighter. Gelato, on the other hand, has no air added to it. This makes the dessert much thicker. Sherbet is a mixture of water and fruit puree. It has very little milk added to it to give it a creamy texture.