A vehicle collision is made up of three distinct parts:

1. The initial vehicle collision, which is the impact between vehicles or objects.
2. The human collision, which occurs when the occupants inside the vehicle collide with interior parts like the steering wheel or dashboard.
3. The internal collision, which involves the movement and impact of internal organs within the occupant's body due to inertia.

These three stages are collectively responsible for the dynamics and injuries sustained during a vehicle crash.