What each number on the meter means
LUFS measures integrated loudness: the signal is K-weighted, a filter that approximates how the ear weighs different frequencies, then averaged over the whole track with quiet passages gated out so a long silent intro doesn't drag the number down. True peak is a different measurement entirely, it's the single highest point the waveform reaches after 4x oversampling reconstructs the signal between samples, reported in dBTP. Sample peak is the highest raw sample value, with no oversampling applied.
Short-term max looks at loudness over a rolling 3-second window and momentary max over 400 milliseconds, both showing how loud the track gets in its busiest moments rather than on average. Loudness range, LRA, measures how much the loudness varies across the whole track in loudness units: a small LRA means a fairly consistent, compressed level throughout, a large one means quiet and loud sections differ substantially.