A sound wave is a type of mechanical wave that travels through a medium, such as air, water, or solid materials. It is created when an object vibrates, causing the surrounding particles to move and transmit energy. This movement creates areas of compression and rarefaction, which propagate outward from the source of the sound. Sound waves can be classified into two main types: longitudinal and transverse. In a longitudinal wave, the particle movement is parallel to the direction of the wave, while in a transverse wave, it is perpendicular. Most sound waves in everyday life, like those produced by musical instruments or human speech, are longitudinal waves.