What is the difference between private and public insurance?

-I'm doing a report on Japanese economy, and I read something about it having mostly public insurance? What does this mean, and what is that difference? What does having a public insurance do for Japan? Like how does it effect the country?Public insurance is government insurance - for health insurance, Medicaid and Medicare. Private insurance, is the insurance that you buy from an insurance company, or your employer buys from an insurance company, for you.