PVC is a plastic used for plumbing, PCV is Positive Crankcase Ventilation.
Now each to their own, but PCV is beneficial for a street car iF DONE PROPERLY.
Each system has their place. You won't see PCV on a race engine.
A poorly baffled rocker cover with a hose going to the carb base plate is bad.
A better system has an air
oil separator allowing any
oil in the air to collect in the container prior to the AIR ONLY going to the intake.
Pulling fresh air into the crankcase and out via a breather hose helps keep hydrocarbon acids from building up in the
oil.
Running breathers only is smelly, messy and bad for the environment.
Google PCV systems.