What does the button with a steering wheel do?

You may find a button with a steering wheel as shown in the image below.

It toggles between 3 different steering modes of the car.

1. Comfort — Makes turning the steering wheel lighter and easier.
2. Normal — Calibrates the steering wheel to give a balanced driving feel. 
3. Sport — Makes the steering a little stiffer for more responsiveness.

Press the button to cycle through the different modes.