Soft Drink refers to nearly all beverages
that do not contain significant amounts of alcohol as hard drinks
do.
The term soft drink is typically used mostly for flavored carbonated
beverages and that is because of advertising. Flavored carbonated
beverage makers were having a difficult time creating national
advertisements due what people call their product varies from place
to place.
In parts of the United States and Canada, flavored carbonated
beverages are referred to as “pop”; in other parts “soda”; in yet
other parts “coke”; and there are a variety of other names commonly
used as well. In England these drinks are called fizzy drinks and in
Ireland called minerals.
Since beverage makers can’t refer to their product in the generic
sense in national or international advertisements due to the varied
terms, they have chosen the term soft drink to be more or less a
universal term for flavored carbonated beverages.