We rarely have to ask how car insurance or home insurance work. What is it that makes health insurance so much more complicated — with individual mandates, single or multiple payers, and so on? Since Congress is (once again) talking about changing how health care works in America, it may be a good time to explain what makes it so strange. This thing we sometimes call “health insurance” is actually a fusion of three different things, only one and a half of which are “insurance” at all. I’m going to walk through the basics you need to know, and end up with a set of four questions you can ask about any health care proposal that will let you understand what people are really talking about.