The units for wavelength and frequency of electromagnetic waves and the speed of light in meters per second and miles per hour should be given.
A wave is a disturbance or variation that travels through a medium transporting energy without transporting matter. The speed of a wave depends on the type of wave and the nature of the medium through which the wave is travelling (e.g., air, water or a vacuum).
The wavelength is the distance between identical points on successive waves.
The frequency is the number of waves which pass through any particular point in one second.