Drinking water is essential to prevent dehydration. However, when you drink water that isn't purified, it quenches less thirst, and you might get multiple negative effects, Thirst and rarely Parasites. Parasites have potential to be a deadly debuff so you should be careful when deciding to drink unpurified water.
Pre-Purified Water[]
Some sources of water are already purified. For example, you can drink rain, which is already pure, by looking up, crouching, and right clicking. You can also find purified water bottles in different kinds of loot chests. You can also get pure water when eating fruits or drinking juice or such drinks.
Purifying Water[]
There are multiple ways to purify water. You can put a bottle or bucket of water in a furnace, you can put water in a cauldron with a fire beneath it, you can put water in a Dragon Canteen, or you can drink it with silver armor on.
Another common way of purifying water is to use a Charcoal Filter on a Canteen.
