There's always confusion around the various forms of drive to all wheels.
This may help give a high level overview of the 3 basic types:
All-Wheel Drive (AWD): AWD systems automatically distribute power to all four wheels as needed, without driver intervention. They are designed for improved traction on various surfaces, making them great for everyday driving in mixed conditions like rain or light snow.
Full-Time 4WD: Unlike part-time 4WD, full-time 4WD is always engaged, meaning power is continuously sent to all four wheels. These systems often include a centre differential or other mechanisms to allow smooth operation on dry roads while still providing off-road capability.
Part-Time 4WD: This system allows the driver to manually engage four-wheel drive when needed, typically for off-road or slippery conditions. When disengaged, the vehicle operates in two-wheel drive, which improves fuel efficiency. However, using 4WD on dry roads can cause drivetrain binding.
Jaguar clearly went the AWD route such that for the vast majority of times the car behaves as RWD, only shifting power around when slipping is detected. Maintains the right handling, balance, performance and fuel economy.
Jeeps, older LR Defenders, etc. are mainly part-time so you physically select 4WD when going off road by locking a centre diff or similar, noting that drive is then always sent to all 4 wheels, with diffs controlling each axle and wheel.
Full-time 4WD is typically used on off road capable SUV's pickup, etc. Land cruisers, Pick up trucks, etc.
Note however that generalisations are difficult as manufactures constantly change between the 3 options based on markets, model focus, technology, etc.