Types of Voltage
There are several different voltage measures such as peak, peak-to-peak, average, RMS, and AC or DC voltage. The difference between them can be seen in the image.
The average voltage is the average value for a certain time period. For pure sinusoidal signals, the average will be zero.
The RMS (root-mean-square) voltage is the square root of the arithmetic mean of the squared function values that define the continuous waveform. It is the most commonly used value to define the AC voltage at a certain point and represents the same energy as the DC voltage at an ohmic load.
The peak voltage describes the highest voltage in a period. In datasheet specifications, the peak voltage or the DC voltage of input are used in the same meaning. To calculate the RMS value for sine waves, the peak value has to be divided by the square root of 2.
The peak-to-peak ratio shows the amplitude of positive and negative peaks in a period.
The Crest Factor is the peak amplitude divided by the RMS value of the waveform.