Question

Where do p and S waves travel? (Like through the earth, on its surface, etc)

Answer 1

The letters "p" and "s" stand for primary and secondary, but they can also be thought of in terms of how they move, p is for "pressure", and s for "shearing", the term "shearing" is a term that means the side-to-side motion of those waves. These waves are "surface waves", waves that travel on the surface of the Earth instead of through it.