Plain water is too, well, plain, for many people, causing them to opt instead for sparkling. Sparkling, seltzer, fizzy, bubbly, club, or soda water is water that has been put under pressure to create fizz. In other words, water is "married" with pressurized carbon dioxide to create those delightful little bubbles that dance all over your tongue.
This kind of carbonated water is sold across the globe as plain, ready-to-drink sparkling water (think San Pellegrino), as part of pre-flavored soft drinks (everything from La Croix to Lemonade), and can also be made at home via special appliances, the most common being Soda Stream.
Discovered way back in 1767, carbonated water became the beverage of choice for many—its only reported downfall (until now) was its acidic nature, which can take a toll on your tooth enamel. Dentists have always been quick to dispel this issue by highlighting soft drinks, in comparison, are about 100 times more erosive for teeth.