db means decibel.
Decibel is a unit of measurement that measures the ratio of two identical units. It is mainly used to measure sound intensity and is commonly expressed in dB. "Min" refers to one-tenth, and the units digit is "bel" (bel). Generally, only decibels are used.
"Bei" is the abbreviation of "Bell" and is a unit named after the outstanding scientist Alexander Graham Bell. Bell obtained a patent for the invention of the telephone in 1876 and made a huge breakthrough in the application and development of the telephone. Bel is not a unit of the International System of Units (System International), but due to the rules of the International System of Units, the first letter of the unit symbol represented by a person's name must be capitalized, so we see that the B in dB should be capitalized. Since the unit "Bel" is relatively large and inconvenient to use, the more commonly used unit is one-tenth of a Bel, which is decibel.