The Bel is a unit of power in the scale of sound intensity, in which 0 Bel is defined as the quietest sound a person with normal hearing can detect.
The loudest sound pressure that can be tolerated has a power level about one trillion times greater. Obviously, a measuring scale with a trillion divisions would be very cumbersome — if a thermometer had a trillion divisions between the coldest and hottest recorded temperatures,, then the difference between freezing and room temperature would be around 144 million degrees.
Instead of a trillion-division linear scale, it was decided to use one in which each higher division represented ten times the power of the previous one. This is a "logarithmic scale", in which each division is one Bel, and the scale ranges from 0 to 12.
Now were have the same problem in reverse — the scale is too small, like a thermometer with only two degrees between freezing and room temperature. But just as we divide a metre (about 39½ inches) into centimetres (about 3/8th inch) and millimetres (1/32th inch), we use 1/10th Bel or deciBel as the common unit.
This gives a convenient scale ranging from 0 to 120 deciBels to represent the range of human hearing. Each 10 dB increase is a tenfold power increase. Because of the nonlinear nature of our hearing, a 6dB increase doubles a sound's apparent loudness (the actual sound pressure, however, quadruples).
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You mentioned "getting into audio recording", a field in which your ears are critical. Always have a sound level meter on hand. NEVER let the playback and monitor levels exceed 100 dB.
You can initially monitor at 90 dB to set levels, EQ, etc., and briefly listen at 100 dB to help get the feel of the mix, but otherwise get the level to 80 - 85 dB and KEEP it there.