The most basic explanation of Comprehensive Insurance is that this is the type (or part) of an insurance policy that covers the policy holder in the event that their vehicle get hit or run into by a deer, bear or other type of wild animal that causes damage to that vehicle; and/or damage done to your vehicle in a natural disaster such as a flood, hurricane, tornado or other event that is totally out of your control.
The first thing that Comprehensive deals with is damage done to your car by a wild animal.
There is absolutely no way that you are going to be able to predict when you are going to have a run-in with a deer (which is the most common cause of automobile damages).
To say that something like this is totally out of your control is a complete understatement! There is no way that you could logically predict if or when you are going to get smacked into by a deer even if you are being very cautious when you see them around.
The same can be said of any wild animal.
The other situations that Comprehensive is also designed for are those in which your vehicle gets damaged in a "Natural Disaster".
By this we mean an Earthquake, Flood, Tornado, Hurricane and other Storm related damages that you would not be expecting and have taken all possible precautions against.
Let's say that there is a nasty thunderstorm or an ice storm that knocks down the power lines and also a few tree limbs...
one of which lands smack dab in the center on the roof of your car.
What are you going to do now; you cannot drive the car like that.
You would take pictures and then call you auto insurance agent and file a claim under your comprehensive insurance, as this fall under the "Natural Disaster" part of that policy.