Sessions matches your exported bounces back to their projects, so you can play any finished idea from a waveform without opening your DAW. Each bounce is measured in LUFS, the loudness measure Spotify, YouTube and Apple Music normalize to, and the reading is said as a consequence rather than a number to go and look up. Level matching changes only what you hear, never the file.
Hear a track without opening Ableton. Sessions matches your exported bounces back to their projects, so you can preview any finished idea from a waveform right inside the app.
How loud your master really is, and what streaming will do about it. Sessions measures each bounce in LUFS, the same loudness measure Spotify, YouTube and Apple Music normalize to, and then tells you the consequence in a sentence instead of handing you a number to go and look up. Platform targets are approximate and written as guidance, never a pass-or-fail badge: how loud the track should be is still your call.