A Rear-Wheel Drive (RWD) system is where the power from the engine is sent to the rear wheels of the car only.
The rear wheels then push the rest of the car forward with the front wheels only being used for steering and braking.
Rear-wheel drive cars tend to have better standing-start acceleration than front-wheel drive cars due to the fact that when a car accelerates the weight of the car is transferred towards the rear of the car. This weight over the rear wheels helps them maintain grip while accelerating.
Due to the fact the the rear wheels of a RWD car push the car through a corner this can sometimes cause the car to slide and spin out if too much power is applied while steering through a corner. There are a lot of modern safety features that aim to prevent this from happening, but drivers should always try to be aware of the limits of their car.