This is a type of spring water that means that the mineral content of the water has not been altered. This is water with dissolved carbon dioxide, either from its natural source or added during the bottling process. Interestingly, carbon dioxide is a waste product that your body removes with each breath. This is the purest form of water that is collected from condensing the steam from boiling water. Most of the minerals and pollutants have been left behind, leaving a tasteless liquid that is the safest to drink.
Some purists add some lemon juice or apple cider vinegar to give it some flavor.
Regardless of the water you drink, drink enough each day and consider drinking it at room temperature. A cold drink slows down the assimilation process in your stomach in the same way an ice pack can reduce blood flow around an area of inflammation. If you suspect the tap water you use for drinking and cooking contains substances you'd rather not ingest, there are a variety of household water filters you may want to consider. Most of the drinking water filters available for home use are granulated activated carbon filters. Carbon has long been used to adsorb impurities and improve the taste of water.