Insurance company guidelines can differ and it would depend upon what struck your vehicle however in general if your car was hit while parked it will probably be your collision coverage that would cover this.
It is most likely that another car hit your vehicle, thus it would be a collision claim for that reason. If a claims adjuster investigates the claim and finds that something else caused the damage, say a deer ran into your parked car somehow, then it would then be a comprehensive claim instead.
You can place a claim with your insurance company and your agent or the insurance adjuster assigned to your claim will advise you under which physical damage coverage, collision or comprehensive, the claim will fall and which deductible amount will be due.