The decibel (dB) is a logarithmic unit used to measure the intensity of sound or the power level of electrical signals. It quantifies the ratio between two values, often comparing a given sound to a reference level. For example, 0 dB represents the threshold of hearing, while sounds above 85 dB can potentially cause hearing damage over time. In addition to sound, decibels are also used in telecommunications and electronics to express gain or loss in signal strength. The scale is non-linear, meaning that an increase of 10 dB represents a tenfold increase in intensity, making it a useful tool for comparing different levels of sound or signal power.