pitch of the string

[Amy]

The pitch of the sound emitted by the emitter is determined by the frequency of the sound.
In the principle of sounding, the more times an object vibrates per unit time (that is, the higher the frequency), the higher the pitch.
All else being equal, the thickness of the strings determines the number of vibrations per unit time, that is, the frequency.
Similarly, the length of the string is different, and the number of vibrations per unit time is different; The tension of the string is different (that is, the tightness is different), and the number of vibrations per unit time is also different.
So the pitch of the string is related to the thickness, length and tightness of the string.