I'll have some sherbe(r)t, spelled correctly either way

Order it in the USA...
and you will get a frozen dessert made primarily of fruit juice, sugar, and water, and also containing milk, egg white, or gelatin

Order it in the UK...
and you will get a kind of fizzy powder sold as a sweet. A popular type of sherbet dip is one where the packet is divided into three or four sections, one contains an edible (candy) stick which can be licked and then dipped into the other sections, each of which contains a different flavour of sherbet (for example strawberry, orange, grape).

BUT order it in Australia...
and you will get an alcoholic beverage, most likely beer.