Radiation is the wave manifestation resulting from the interaction of an electrical and magnetic fields perpendicular to one another.
Waves are transverse.
Wave train is infinite in both directions. Identify two properties of electromagnetic waves. The linear distance between one point on a wave and the corresponding point on the next wave. When energy is absorbed or liberated by matter it occurs in packets of energy discontinuously. Energy only appears to be exchanged continuously because of the exchange on the atomic level being asynchronously resulting in a continuum of energy exchange.