A wave differs from an oscillation in that the time-varying quantity also depends on position. Usually the nature of the disturbance is directional, and the result is a longitudinal wave if this direction is the same as the direction of motion of the wave, or a transverse wave if it is perpendicular to the direction of motion.
Most waves travel through a medium, the properties of which determine the speed of the wave.
In the case of an electromagnetic wave , the disturbances are the electric and magnetic field strengths. The New Penguin Dictionary of Science 2. sound The New Penguin Dictionary of Science 3. The New Penguin Dictionary of Science 4. A Dictionary of Science, Oxford University Press 5. All rights reserved.