Health insurance is a type of insurance coverage that provides financial protection against medical expenses and healthcare costs. It is designed to help individuals and families manage the high costs of medical treatments and services. Health insurance policies can be purchased from insurance companies or provided by employers as part of employee benefits.

Here are the key features of health insurance:

1. Medical Coverage: Health insurance policies cover a wide range of medical expenses, including hospitalization, surgeries, doctor's fees, diagnostic tests, prescription drugs, ambulance services, and more. The extent of coverage depends on the specific policy and its terms and conditions.
2. Premiums: Policyholders pay regular premiums to the insurance company to maintain health insurance coverage. Premiums can be paid on a monthly, quarterly, semi-annual, or annual basis.
3. Deductibles and Co-payments: Some health insurance plans may have deductibles, which are a specified amount that the insured needs to pay out of pocket before the insurance coverage starts. Co-payments are fixed amounts that the insured must pay for certain medical services or prescriptions.
4. Network Providers: Many health insurance plans have a network of healthcare providers, including hospitals, clinics, and doctors. Visiting network providers often results in lower out-of-pocket costs for the insured.
5. Pre-existing Conditions: Health insurance policies may have exclusions or waiting periods for pre-existing medical conditions. A pre-existing condition is an illness or ailment that the insured had before obtaining the insurance policy.