The decibel (dB) is a logarithmic unit used to quantify ratios of power or intensity, making it useful for describing phenomena that span many orders of magnitude. Because it operates on a logarithmic scale, the physical quantity being measured—such as sound intensity, signal strength, or voltage—must be raised to the power of ten to determine the corresponding decibel value. In acoustics, sound levels are measured in decibels, with the scale approximating human perception of loudness. In electrical engineering and telecommunications, the unit measures power ratios and is used to quantify signal loss or gain across transmission media, providing a standardized way to compare vast differences in energy levels objectively.