Short term loudness
This is the briefly measured loudness. This happens over a period of 3 seconds.
Momentary loudness
This is the current loudness which is measured within 400ms.
Integrated loudness
Integrated Loudness determines the average loudness over the entire playing time. As a rule, a “relative gate” is also used here. This means that signals which are below a certain limit are not used to calculate the average loudness. According to EBU 128, the limit is, for example, -23 LUFS.
volume and loudness
Loudness is often confused with loudness. In short - volume happens on your end device such as the music system or smartphone. Here you can control the volume. Loudness is also a subjective and relative term. However, if one speaks of loudness, this is a firmly measurable value that is not only relevant for the sound in the master, but also for streaming on Spotify, Youtube and Co.