Answer
Pitch is "highness" of the sound while loudness is related to "intensity or amplitude" of sound.
Work Step by Step
The pitch of a sound wave tells us how high( shrill) or low (bass) is a sound.
The loudness of a sound wave on the other hand refers to its intensity or amplitude.
For example, a flute and a trumpet can play the same note, but the pitch of the trumpet can be higher than flute since it is more shrill or high note.
