P wave or primary wave
P-wave is the fastest but the least dangerous because it is of the “compressional” type.
S-wave or secondary wave
the S-Wave travels at a speed of about half the speed of the P-Waves and is a wave that releases energy in the “transverse” direction with respect to the direction of propagation.
R/L waves also called surface waves
R/L Waves also called “surface” waves are by far the least fast but very damaging because they cause the ground to “vibrate” according to elliptical and retrograde orbits (R wave), as when a stone is thrown into water, and in the horizontal and transverse plane (L wave), resulting in the greatest shaking of buildings.