The decibel simply specifies the ratio of the magnitudes of like quantities, and is never ambiguous because, for example, when referring to voltage, -  or current, or weight, or pressure, or any other scalars:

$$ dB = 20 \log_{10} \frac{V1}{V2} $$

However, when time gets involved and movement of a force through time becomes power,

$$ dB = 10\log_{10} \frac{P1}{P2} $$