A soft drink is any water-based flavored drink, usually but not necessarily carbonated, and typically including added sweetener. Flavors used can be natural or artificial. The sweetener may be a sugar, high-fructose corn syrup, fruit juice, a sugar substitute, or some combination of these. Soft drinks may also contain caffeine, colorings, preservatives and other ingredients.
Soft drinks are called "soft" in contrast with "hard" alcoholic drinks. From Wikipedia
