What type of wave is shown traveling through tye core explain why this is the only wave type shown in the core?

The wave traveling through the Earth's core is a P-wave (primary wave), which is a type of compressional wave. P-waves can travel through both solids and liquids, making them the only seismic wave type that can propagate through the Earth's liquid outer core. S-waves (secondary waves) cannot travel through liquids, which is why they are not observed in the core. This distinction helps scientists infer the composition and state of the Earth's internal layers.