A decibel (dB) is a unit used to measure the intensity of sound. It quantifies how loud a sound is compared to a reference level, typically the faintest sound the human ear can hear. The decibel scale is logarithmic, meaning that an increase of 10 dB represents a tenfold increase in sound intensity. Decibels are also used in various fields, such as telecommunications and electronics, to measure signal strength. For example, in audio engineering, a sound level of 60 dB is considered moderate, while sounds above 85 dB can potentially cause hearing damage over time.