Comprehensive car insurance covers damages from an "act of God," or events that are not caused by a car driving into something else. An "act of God" can include things like damage from a heavy tree branch falling on your car. Since you have no control over when or why a tree branch would fall on your car, this kind of accident would be covered under your comprehensive policy.
The legal liability of the insured person is covered under the third-party insurance policy in the case of disability or demise of the third party, and any damage or loss to the property of the third party. The third-party liability policy takes care of the financial and legal burden in such circumstances. Despite the fact that the direct beneficiary is neither the insurance company nor the insurer, but a third party, this is the most crucial benefit that a third party insurance secures for the owner or the driver of the insured vehicle.
The Insurance Information Institute suggests that you take the amount you'd pay in one year for comprehensive and collision coverage, and multiply that number by 10. Is your car worth less than that number? Then comprehensive and collision coverage might not be a cost-effective option for you. In other words, you might want to talk to your agent about whether it makes sense to include these coverages on your car insurance policy.