Basically, you stay at home and your parents teach you in the comfort of your own home. Just you and the "teacher", one on one. No class or anything.
It can work pretty well if you have competent "teachers" because you move at your own pace and can concentrate more on whatever you damn well please. Let's say you don't like history. Maybe you'll only spend an hour a day on history but if you really like science, you can spend three hours on it and really delve into the aspects of science that you enjoy.
Homeschooling also helps if you don't like putting up with ****ty school bureaucracies and stupid school politics where the ass-kissing rich parents who are on the school board get everything for their kids, while everyone else gets screwed. Then again, that's life and it's not such a bad thing to learn to deal with it early on.