A waveform is a representation of how alternating current (AC) varies with time. The most familiar AC waveform is the sine wave, which derives its name from the fact that the current or voltage varies with the sine of the elapsed time. Other common AC waveforms are the square wave, the ramp, the sawtooth wave, and the triangular wave. Their general shapes are shown below.
Amplitude is the maximum displacement of points on a wave, which you can think of as the degree or intensity of change. This maximum displacement is measured from the equilibrium position. The following picture shows a diagram of a sine wave. The diagram shows amplitude and wavelength, which is the distance between two successive like points on a wave. Wavelength is like the distance between two adjacent peaks or two adjacent valleys. Stated another way, wavelength is the time required to complete one full cycle of the wave.
Frequency is important in wireless communications, where the frequency of a signal is mathematically related to the wavelength. If f is the frequency of an electromagnetic field in free space as measured in megahertz, and w is the wavelength as measured in meters, then