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.
Some communities prefer to create virtual insurance amongst themselves by other means than contractual risk transfer, which assigns explicit numerical values to risk. A number of religious groups, including the Amish and some Muslim groups, depend on support provided by their communities when disasters strike. The risk presented by any given person is assumed collectively by the community who all bear the cost of rebuilding lost property and supporting people whose needs are suddenly greater after a loss of some kind. In supportive communities where others can be trusted to follow community leaders, this tacit form of insurance can work. In this manner the community can even out the extreme differences in insurability that exist among its members. Some further justification is also provided by invoking the moral hazard of explicit insurance contracts.
Earthquake insurance is a form of property insurance that pays the policyholder in the event of an earthquake that causes damage to the property. Most ordinary home insurance policies do not cover earthquake damage. Earthquake insurance policies generally feature a high deductible. Rates depend on location and hence the likelihood of an earthquake, as well as the construction of the home.
Let's use the aftermath of a major storm to illustrate the differences between collision and comprehensive. Within that storm, let's consider two hypothetical events: First, a heavy telephone pole was blown down and fell on your truck, or second, you swerved to avoid a falling tree and wound up crashing into a guardrail. In the first event, you couldn't control when or why a tree fell on your car. This kind of accident would get reimbursed under your comprehensive policy. In the second situation, you were driving the car and ultimately swerved into the guardrail. This makes it a collision, and collision insurance pays for the damages.