Water is the one thing that every living creature needs to survive. In order to survive you need to be able to find water and sterilize it. Water should always be brought to a rolling boil for at least 5 min to kill most of the germs in it.
The first way to get water is out of a lake or stream pretty self explanatory just be sure to boil it before drinking. If the water appears to be stagnant dig a hole about a foot away from the water let the hole fill up and drain it twice then the third time the water should be safe to drink.
Another way is from the sky and the grass. Rainwater can be collected on a tarp or in any container you have. Rainwater is safe to drink without boiling and tastes great. You can put rags on your ankles to collect dew and ring out the rag.
The final way is in a snowy environment turn the snow into water. NEVER EAT SNOW it will just dehydrate you and give you frostbite on your face as well as lower your core temperature. Instead melt the snow in a container and drink it remember your whole container full of snow will only be half full once melted because snow is mostly air.
Hopefully this page will help in a survival situation.