The aim of this lecture is to describe Wave Types and Characteristics. There are two types of wave: transverse and longitudinal. Transverse: The displacement of the particles of the medium is perpendicular to the direction of wave propagation. Longitudinal: The displacement of the particles of the medium is parallel to the direction of wave propagation. Mechanical Waves are waves which propagate through a material medium (solid, liquid or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves.