I know it is confusing to say the least.
The whole 4 or 8 cups a day is a general rule and in reality we all need much more than that.
If you are active you will need around 4 litres and that should be checked by a nutrition expert.
Water is required for so many chemical reactions that happen inside our bodies.
Water is a vital nutrient basically.
The quality of your water is also important.
I am not saying that you must be drinking mineral water, and that is not recommended since mineral water has a high sodium intake and should only be consumed once in a while.
Filtered water is the way to go.
Always filtered, always.
There are so many filters on the market, get one and go for it.
I recommend filters that also turn your water into alkaline water.
Tap water is fine only if filtered, to removed heavy metals and debris produced during the water moving around metal pipes.
So have filtered water, aiming for around 3 to 4 litres a day.
Anything above that should be checked with a nutrition expert !
Stay hydrated guys.
4 glasses, 2 litres; what is the right water quantity one should have everyday?