Seismic waves are vibrations that travel through the Earth, typically generated by events like earthquakes or volcanic eruptions. These waves move through the Earth's layers, including the crust, mantle, and core, and can be detected by instruments called seismometers. There are two main types of seismic waves: P-waves, which are primary waves that compress and expand the material they move through, and S-waves, which are secondary waves that move the ground up and down or side to side. Seismic waves provide valuable information about the Earth's internal structure and help scientists understand geological processes. By analyzing the speed and path of these waves, researchers can determine the composition and state of different layers within the Earth. This knowledge is crucial for assessing earthquake risks and improving building designs in vulnerable areas.