In North America, the word “Sherbet” connotes a frozen dessert, which you could categorize somewhere in the middle between sorbet and granita (being the lightest of such frozen desserts) and ice cream (being the richest.)
The principle ingredients in Sherbet are water, fruit juice, sugar, and milk or cream. It may also have egg whites and gelatin, but by American law, Sherbet must contain at least 1 to 2 % milk fat.
If the Sherbet you are presented with is a frozen dessert without either dairy or egg, then it is in fact actually sorbet.
Sherbet is stirred constantly while the mixture is being frozen in order to keep the ice crystals very small.
In the UK, Sherbet is a fizzy candy powder
History Notes
Sharba is an Arabic word meaning “to drink.”
Originally, Sherbet was a Middle Eastern sweetened fruit juice drink sold by street vendors. It was called “sharâb” in Persian. Over time, a version emerged with alcohol in it, called “sharbât” in Arabic, and “şerbet” in Turkish.
By the 1500s, “sharbât” had became a fashionable drink in Europe.
Over time, as it became possible to freeze things, it started to be served frozen.
Language Notes
Some English speakers mistakenly pronounce the word, “sherbert.”