Mechanical waves are disturbances that travel through a medium, such as air, water, or solid materials. They require a medium to propagate and can be classified into two main types: transverse waves, where the medium's displacement is perpendicular to the direction of wave travel, and longitudinal waves, where the displacement is parallel to the direction of wave travel. These waves play a crucial role in various phenomena, including sound, seismic activity, and ocean waves. For instance, when you speak, sound waves travel through the air, allowing others to hear you. Understanding mechanical waves is essential in fields like acoustics and engineering.