Smooth and curved motion that moves on a surface. It is mainly associated to the water and comes from latin unda, ae ("Eddy, wave of water"). As waves in a liquid move radially and the bounce back will interfere with each other, is understood also by extension as 'wave' to those produced by sounds in the air and radiation that is scattered. In fact, radio emissions, which allow to communicate remote gave rise to the meaning "to have or to be in wave" to nominate something "in tune", modern and who communicates well with your environment. The graphs of these signals are also called waves.