Driver Assistance - human driver operates the car, but with assistance from an automated system for steering or acceleration (but not both).
Partial Automation - automated assistance is offered for both steering and acceleration, but the driver is still responsible for safety-critical actions.
Conditional Automation - sensors monitor the surrounding environment and the additional activities are automated such as braking. The driver must be ready to intervene should the system fail.
High Automation - the vehicle can operate fully autonomously but the mode can only be activated under specific conditions.
Full Automation - the driver specifies the destination and the car does the rest on its own. At this level, there is no need for a steering wheel or pedals.