Vapor Pressure. The Macroscopic View. The vapor pressure of a liquid is the equilibrium pressure of a vapor above its liquid (or solid); that is, the pressure of the vapor resulting from evaporation of a liquid (or solid) above a sample of the liquid (or solid) in a closed container.
Transverse and longitudinal are two different types of waves. The main difference between transverse and longitudinal waves is that in transverse waves, oscillations occur perpendicular to the direction of propagation of the wave, whereas in longitudinal waves, oscillations occur parallel to the direction of propagation of the wave.
Longitudinal waves, also known as l-waves, are waves in which the displacement of the medium is in the same direction as, or the opposite direction to, the direction of travel of the wave.