Eli5: Why does sea water kill us but electrolyte solutions actually hydrate us? Aren’t they both water + salts?

Question

Edit: Question answered. Thanks!

Don’t be too hard on me, I almost failed chemistry:'(

In: 2220

Answer 1

That much salt can kill you, so your body has to push it out, but to push it out your body needs more water than you drank to do it.

So to keep yourself from getting sick from the salt water, you pee out more water than you drank. So after you drink salt water you need more water than you did before. That’s bad.