Comprehensive coverage is a type of auto insurance that covers damage on your car that is not caused by collision. You might think that comprehensive means full coverage but it's not true. Theft, vandalism, fire, natural disasters, animal strike, civil disturbance and falling objects are example items covered by comprehensive insurance. As long as you didn't collide your car with another car, comprehensive coverage will pay to repair the damage. It seems like "not-so-important" insurance, but you can't predict when those accident will occur. It's better to have coverage rather than having unexpected expense, and we know that auto repair can costly. 

Collision coverage covers damage to your vehicle caused by collision with another vehicle or object. The insurance company covers your vehicle regardless who is at fault. For example, you hit a tree or a pole, crash with a building, bump into another car, rolling your car, or being hit by another car. Collision coverage comes with a deductible. Let say another car hit your car, but you use your coverage, you still owe your deductible. Your insurance company should try to recover your repair costs from the fault party. If it's successful, then your deductible may be refunded. 

Both types of coverage are optional, it pay for damage to your car and come with deductibles as well. They have different items to cover and it's not futile to purchase both coverage for solid protection. Since collision claims are likely caused by "human error", the insurance rates expect to rise. Meanwhile, comprehensive claims are coming from something you can't control, the rates should not rise. Furthermore, some state laws against rate increases related to comprehensive auto insurance claims.