Car insurance basically covers you, your passengers and your car in case of an accident.
Many states require you to carry liability coverage in your insurance policy. Liability insurance covers the expenses incurred for the damages for another vehicle with your own if you are at fault. So basically if you are in an accident and you caused the damage, then the liability of you car insurance will cover damages according to the terms that are in your policy.
Collision coverage is when your car insurance will pay for the repairs or replace your car in the case of an accident.
Comprehensive coverage helps you pay for damages to your vehicle that occurs with bad weather, theft and vandalism.
As you would will all insurances, your car insurance will also a deductible. The deductible amount of the claim is your responsibility to pay. Car insurance costs go up as you lower your deductible. If you want to have a higher deductible you car insurance will be less expensive.
Also keep in mind that as your car ages your car insurance premium will decrease in price. Of course that is if you have a good driving record and dont get any tickets or get into...