glossary
Sample peak is the tallest stored sample. It is useful for clipping checks, but it is not the whole loudness story.
Sample peak level reports the highest individual sample in a digital signal. In a DAW, that usually appears as dBFS peak on a channel or bus meter.
It tells you whether stored samples have reached full scale, which is important for avoiding obvious digital clipping.
Two mixes can have the same sample peak and feel completely different in loudness. A snare transient can set the peak while the rest of the mix remains quiet.
Sample peak also misses inter-sample peaks that can appear during conversion or encoding.
Use sample peak to catch clipping inside the session, then use true peak for delivery margin and LUFS or RMS for level over time.
If you only chase sample peak, you can end up turning down the wrong thing or pushing a limiter without understanding the actual loudness.