Decibel

Decibel(dB) is the unit of measure for the power of an electrical signal or the intensity of a sound. The logarithmic decibel scale is used to indicate the amount of gain an amplifier or antenna provides, or the loss introduced over wires. Positive numbers represent amplification, and negative numbers represent loss.

On the decibel scale, every 3dB represents a 2x increase, and every −3dB decrease represents 1/2. 10dB represents a 10x increase, 20dB represents 100x, 30dB represents 1000x, and so on.