On the flip side, water made in a glass is prone to air-borne and dust particles bacteria.
On the flip side, when water is exposed to atmosphere, it absorbs a tiny section of which is converted into carbonic acid, carbon dioxide. To put it differently, this means that water subjected to atmosphere is prone to shifting its chemical structure. To be particular, carbon acid converts into bicarbonate or carbonate when it discharges one or two protons, which alters the water pH. Its flavor is also affected by this change.
Thus, the next you feel upon waking up, thirsty, just jump to your own kitchen and acquire some fresh water.(Source)