Don’t confuse these two coverages, they are different.

I’m going to first talk about property damage coverage. 

You are required to have property damage coverage on your car policy.  Property damage covers damage you cause to someone else’s car or property when you are at fault in an accident.  The minimum property damage coverage by law is $5,000.  No deductible applies to this coverage.  Be sure to talk to your agent, I would never recommend the minimum amount required by law.  Keep in mind, most vehicles to repair or replace would likely be more than the minimum amount.

Physical damage is different from Property damage coverage.

Physical damage is comprehensive and collision coverage for your car.  Comprehensive coverage is fire, theft, vandalism, and earthquake.  Collision coverage is just that, anything that you might hit while driving your car.  Physical damage pays for damage to your car minus a deductible.  The deductible is the amount you pay out of pocket.  The higher your deductible the lower your premium.