Lots of carmakers boast of torque vectoring, but they’re not, strictly, saying the same thing. Only by knowing their technology can you have much idea of the result they’ll get.
The principle is to send different drive torque to each tyre to help control and steer the car. Around a bend, if the outside rear tyre gets extra drive, it’ll rotate the car towards the apex and cancel understeer. Speeding up the inside one quells oversteer.
The best way to do this is to control the output at the rear driveshafts. In 4WD cars this depends on the centre power take-off’s programmed clutch packs pushing extra drive to the rear, and a controlled rear diff pushing some of this surplus to the outer rear tyre. It’s what helped make Mitsubishi Evos and Nissan GT-Rs so magical. However it depends on epic mechanical and hydraulic complexity in the drivetrain.
Another approach is used by the Ford Focus RS and transverse engine Land Rovers (rear axle) and Ferrari Lusso (front axle). They have clutch packs and no diff at each driveshaft to control the speed each wheel is driven.
The budget alternative is to brake the inner tyre. This puts a drag on that side of the car, pulling its nose toward the apex. These systems use an open rear differential, which will – provided the prop shaft speed is constant – have the effect of overspeeding the outside rear wheel to the degree the inside one is slowed. But overall you