Audio
Parameters
The time intervals of the bars throughout the track. A bar (or measure) is a segment of time defined as a given number of beats. Bar offsets also indicate downbeats, the first beat of the measure.
The time intervals of beats throughout the track. A beat is the basic time unit of a piece of music; for example, each tick of a metronome. Beats are typically multiples of tatums.
Analysis meta information (limited use)
Sections are defined by large variations in rhythm or timbre, e.g. chorus, verse, bridge, guitar solo, etc. Each section contains its own descriptions of tempo, key, mode, time_signature, and loudness.
Audio segments attempts to subdivide a song into many segments, with each segment containing a roughly consitent sound throughout its duration.
A tatum represents the lowest regular pulse train that a listener intuitively infers from the timing of perceived musical events (segments).
An analysis of the track as a whole. Undocumented on Spotify's side.