The key difference in collision vs. comprehensive coverage is that, to a certain extent, the element of the car driver's control. As we have stated before, collision insurance will typically cover events within a motorist's control, or when another vehicle collides with your car. Comprehensive coverage generally falls under "acts of God or nature," that are typically out of your control when driving. These can include such events as a spooked deer, a heavy hailstorm, or a carjacking.
For some, the best coverage is the cheapest car insurance policy that makes them able to legally drive on the road. For others, the best coverage is the type that covers the full cost of repairs on your vehicle when you file a claim. The only way to be certain you are fully protected is to purchase both comprehensive coverage and collision coverage. Each coverage has its own job to do.
Let's use the aftermath of Superstorm Sandy as an example to illustrate the differences between collision and comprehensive. Within that storm, let's consider two events that might have happened: 1) a heavy tree branch fell on your car, or 2) you swerved to avoid a falling tree branch and wound up crashing into a tree. In the first event, you had no control over when or why a tree branch would fall 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 tree, which makes it a collision, and collision insurance therefore pays for the damages. Events like the hypothetical ones stated above are why it's important to differentiate between the two types of coverage.