Machine regulated refers to the fact the alternator is regulated by an onboard device as distinct from a remote one, in each case by varying the field current to control the max voltage the battery receives from the alternator stator. Modern cars employ dedicated circuitry within the ECU to control the field remotely I whilst also providing a lower voltage float mode when battery is deemed fully charged much like a smart battery chargers but with the advantage of responding efficiently to changes in load. Remote regulation also provides voltage sensing at the battery rather than machine, compensating for any voltage drop.
Whatever system a car uses you should be seeing above 14 volts at the battery after a start, assuming revs are a little over idle, in order to replenish after the battery drain.
