What is the difference between Audi A8's adaptive cruise control and lane keep assist features?

I am trying to understand the different advanced driving assistance systems (ADAS) available on the Audi A8 model. What does the adaptive cruise control feature do and how is it different from the lane keep assist feature? Are there any other similar features that I should be aware of?

The adaptive cruise control feature in Audi A8 uses radar sensors to maintain a safe distance from the car ahead. It can also adjust the speed according to the traffic flow. As for lane keep assist, it uses cameras to detect road markings and gently steer the car to keep it in the lane.