Level 8 corresponds to a light blonde on the universal colorimetry scale (1 = black, 10 = lightest blonde). It measures the lightness or darkness of hair, independent of the reflect.
The copper (.4) reflect is the most intense in the warm family. It adds orange-red tones that create dimension and vibrancy. Very on-trend ("copper" is one of the most searched colors) but requires more maintenance than neutral reflects.
Each brand codes level and reflect differently. The table above shows how the major professional brands name this same shade: level 8, copper reflect.