In brief
The function is different from the constant comfortable centering.
Useful to know
Emergency holding in the lane can counteract with steering when leaving it creates an immediate risk of collision. Bosch describes the use of camera and radar to assess the critical situation. [1]
This is a different task than constantly keeping the car close to the middle of the lane. When considering equipment, check the activation conditions, not just the general label "band assistant". Environmental recognition and possible intervention have limitations. The description of the function does not mean permission for the driver to change lane without checking the adjacent traffic.
Sources
For further detail and to check the information: