Liability insurance coverage on a personal auto policy follows the driver no matter whose vehicle is being operated, provided it is an eligible vehicle. All states, except for one (New Hampshire), require at least liability coverage. Liability coverage protects the insured (i.e., follows the driver) when the insured operates a vehicle owned by someone else. In such a situation, they will still usually be covered under their own auto insurance policy. However, the best rule of thumb in looking for coverage under a policy is to begin with the exclusions.
Collision coverage has a deductible, which is the amount you pay before your coverage helps pay for your claim. You can typically choose the amount of your deductible when you buy coverage. So, if you choose a $1,000 deductible and your car is later damaged in a covered accident, you'd have to pay $1,000 toward repair costs. Your collision coverage would help pay the rest, up to your coverage limit.