Four-wheel drive is a system where torque is distributed to all four wheels of the vehicle. It is beneficial in some circumstances such as providing increased traction in tricky weather conditions, but is most suited to off-road driving.
The drivetrain warranty covers parts of the car, such as the engine, transmission, driveshaft, etc. Typically longer than the basic warranty, it lasts for a certain number of years.
This allows all four wheels to move up and down independently, providing a smoother ride when, for example, going over bumps in the road.
The turn radius indicates the smallest circular turn a car can make. With a smaller turn radius it is easier to perform a U-turn in one attempt instead of having to reverse back and forth in order to turn around.
Front-wheel drive is the most common type of drivetrain and offers several advantages. It is cheaper to manufacture (reducing the cost of the vehicle) and also lighter which helps improve fuel economy. Due to having the weight of the engine over the drive wheels it also benefits from increased traction.
The basic warranty of a car covers all aspects other than parts which are subject to normal wear and tear, such as windscreen wipers and brake pads. It lasts either a certain number of years or amount of kilometres driven.