The two halves of the name describe the two jobs. Access control decides whether a vehicle may enter, using a ticket, a plate read, a permit or a credential. Revenue control handles tariffs, payment, validation and the reporting that proves the money collected matches the vehicles that used the site.
PARCS is the language of car park operators, retail landlords, airports, hospitals and local authorities, where parking is either a revenue line or a resource the public competes for. It is not usually the right frame for a staff car park behind an office, where nobody pays and the real problem is rationing a small number of bays fairly across a hybrid workforce. That is parking management in the workplace sense, and it is closer to booking a desk than to running a toll.
The two do meet on mixed sites. A hospital charges visitors through a PARCS installation while allocating staff bays through a separate workplace system, and ANPR hardware installed for enforcement can also verify that whoever booked a bay is the one parked in it.