A car with driver is simply a private vehicle that stays with you for a planned part of the day. Instead of booking separate one-way rides, you agree a start time, a rough list of stops and a time to be back at your hotel or villa. Between the stops the driver parks nearby and is ready when you are.
It is not self-drive car hire. You do not need a driving licence, you do not sign a rental contract, and you do not have to worry about fuel, tolls, insurance excess or finding a parking space in Kaleiçi on a busy afternoon. It is also different from a group tour: nobody else is in the car, and the order of the day is yours.
If you are still weighing up the options, our comparison of private transfer versus taxi in Antalya explains why a pre-agreed price is easier than a meter.