Why can't we drink saltwater?

More than 70% of our little blue planet is covered by water, but we can only drink a tiny fraction of it. Why can't we drink saltwater when it is all around us?

Why can't we drink saltwater?
More than 70% of our little blue planet is covered by water, but we can only drink a tiny fraction of it. Why can't we drink saltwater when it is all around us?