A mechanical wave is a disturbance that travels through a medium, such as air, water, or solid materials, transferring energy from one location to another. These waves require a medium to propagate, meaning they cannot travel through a vacuum. Common examples of mechanical waves include sound waves and water waves. Mechanical waves can be classified into two main types: transverse waves and longitudinal waves. In transverse waves, the medium's particles move perpendicular to the direction of the wave, like ripples on a pond. In longitudinal waves, the particles move parallel to the wave's direction, as seen in sound waves, where compressions and rarefactions occur.