All Perils under Section C for automobile and its equipment physical damage coverage is the widest form you can purchase. It is more then a combination of collision and comprehensive. An extra coverage that is included is theft of the vehicle by a family member. One deductible applies if you have a claim.
The term "All" is a little misleading. There will always be exclusions under an insurance policy. There are some things, such as radioactive clouds or war that cannot be insured. It is up to the government or general public to deal with a loss that huge.
Some insurance companies will give a discount for combining the collision and comprehensive portion under the All Perils.
All Perils for automobile is not All Risks which is often used as a term in property insurance. Again, there will be exclusions and limitations on a policy for your home or your business.
Review your policy wordings and discuss your options with your agent or broker. Buy what you need for your situation.
All Peril