A pressure wave is a disturbance that travels through a medium, such as air, water, or solid materials, causing changes in pressure. These waves are often generated by events like explosions, earthquakes, or even sound. As the wave moves, it compresses and expands the medium, creating areas of high and low pressure. In the context of sound, pressure waves are responsible for transmitting sound energy from one location to another. When an object vibrates, it creates pressure waves that travel through the air, allowing us to hear sounds. This phenomenon is essential in various fields, including acoustics and seismology.