The point cloud is under the vehicle frame or lidar sensor?

[GANWANSHUI]

Hi, when I use the point cloud, I am a little confused about the point cloud is under the vehicle frame or lidar sensor.
If I want to obtain the point cloud under the vehicle frame, do I need a further transformation? Thank you very much!

The extrinsic shows that it is under the vehicle frame, but what is the definition for m[pose]. Thank you very much!