Tuning: Equal Temperament
If you tune every open string and every pedal pull to be in tune with A=440Hz or 0 cents on an electronic tuner, you are splitting the octave into 12 equally spaced notes.  This is referred to as EQUAL TEMPERAMENT.

Some string and pedal combinations will sound more in tune

Some tones (e.g., the third, sixth) may sound strange to the ear