Signal to Noise Ratio
From GEAR Software Knowledgebase
A measurement describing the dynamic range of an encoding system, storage or transmission system, or playback system. Measured in decibels, the signal to noise ratio is calculated by taking the peak signal amplitude and dividing it by the noise floor (the peak level of background noise in the system). The greater the signal to noise ratio, the higher the quality of the system, and the greater the range of signals that can be resolved without distortion (from quietest to loudest in the case of audio, or from brightest to darkest in the case of video).