A Basic question about the headlight symbols for Volvo XC90?
 

I bought a Volvo XC90 2006 just recently and I am not very familiar with the headlight system or the signals for it. I have read the manual regarding the headlight but I don't really understand it. Does Volvo XC90 2006 have an automatic headlight that adjusts to the current level of light? Also how does the light exposure of the following symbols differ: 0, two little circles with lights, and one big circle with lights? (I apologize for these crude descriptions idk how else to describe it). What should I set the light level to to maintain optimal results without my headlights burning out?