Soda water, also known as club soda is water containing carbon dioxide, which bubbles out and makes the drink tasty and peculiar. Historically, the first soda waters were prepared by adding sodium bicarbonate to lemonade. A chemical reaction between sodium bicarbonate and citric acid occurred to create carbon dioxide.

The first successful carbonated water was made by Joseph Priestley in 1796 who was trying to imitate the naturally occurring effervescent water that bubbles up from underground springs and was thought to be beneficial to health.

Currently, soda water is made by passing pressurized carbon dioxide through water. This increases the solubility i.e. more CO2 dissolves than under standard atmospheric pressures. When the pressure is reduced e.g. by opening the bottle, the gas comes out of solution forming the characteristic bubbles.

Soda water is considered by some to be good for removing stains. For example coffee stains from mugs, or stains from silver. A frequently used method of preventing red wine stains from setting in is to sprinkle salt on the stain and then applying a liberal amount of soda water.

The most popular forms are flavored, and referred to as soda pop. These are widely sold throughout the world. Major brands include: Coca-Cola, Pepsi, R.C. Cola, 7-Up, and Dr Pepper. Many sales of these beverages are made via vending machines.