Carbonated water (also known as soda water, sparkling water, fizzy water, club soda, water with gas, in many places as mineral water or (especially in the u.s.) as seltzer or seltzer water) is water containing dissolved carbon dioxide gas, either artificially injected under pressure or occurring due to natural geological processes. carbonation causes small bubbles to form, giving the water an effervescent quality. common forms include sparkling natural mineral water, club soda, and commercially-produced sparkling water. club soda and sparkling mineral water and some other sparkling waters contain added or dissolved minerals such as potassium bicarbonate, sodium bicarbonate, sodium citrate...

Source: Wikipedia