Explanation of the Pedal Marks on a Piano
The pedals of the piano each create a different effect when utilized. Composers tend to favor the sustain pedal, as it is the pedal that gives the piano the strongest reverberation between the notes. Pedals are not always depressed entirely; you can depress a pedal at differing degrees to create a stronger or weaker effect. It is mainly up to the pianist to use his judgment on how far to depress a pedal.