Health insurance is the system we use to pay for healthcare. Insurance is made available by your employer, you then pay premiums in order to buy and keep your insurance, and once you actually need healthcare, your insurance helps cover some of the costs of receiving care.
Everyone in the states needs health insurance, not because of how affordable it makes taking care of emergencies, but because, if you don't have insurance, you have to pay the prices that the medical provider and insurance companies made up on how much procedures cost, so they can give each other a discount on those insane prices.
For instance, if you have insurance in the states and you go to the hospital for a nasty fall that maybe broke something. Nothing was broken, but they had to take x-rays. Well, you have to pay for the x-rays, and the time that the staff was needed for you. We're going to pretend, for this case, that your insurance won't deny coverage since it "wasn't medically necessary". So you'd get a bill between $200-$300.
But if you didn't have insurance, or were denied coverage, you have to pay full price. But that price isn't the price that anyone actually pays unless they're in your predicament. You see, the provider and insurance had gotten together to determine how much would be paid for any given procedure, but they make the deal seem much better to their respective bosses by inflating the price of the procedure before negotiations, so that the insurance pays a "discount" that's similar to the actual cost of the procedure. Which is great for them, but if you get treatment without insurance (or your insurance denies coverage) you have to pay the fake, inflated price that the provider said it cost before they negotiated the price back down to something reasonable with the insurance companies. So, to go back to my example above, those x-rays and some time with staff that didn't lead anywhere will probably cost you more in the neighborhood of $2000-$3000 if you aren't covered.
This has a double cooling effect. One, it forces more people to have health insurance out of fear of paying those stupidly insane prices. And two, it makes people avoid going to the doctor for minor issues for fear of being denied coverage since "it wasn't medically necessary". Great for profitability, terrible for humans.