If earth has so much water, why do people in some areas have none to drink. Explain?

Although there is alot of water on earth some of it is contaminated and could be harmful for us to drink. Therefore people don't drink it in order to not get sick.

Even though our planet has a lot of water, some areas don't experience rain much and they aren't close to large bodies of water.

So in those areas they don't get to drink much water, because there isn't much available.

We may have a unlimited supply of water, but in other countries they might not. Hot, humid area's that don't experience rain won't have any water to drink, so they go to extreme measures and drink from cactus, or eat cactus fruit.

Also, most of the water on earth isn't drinkable which can cause sickness.