Apple Health has been expanding in scope for years now, What started as just tracking workouts it now has features including heart, medications, mental wellbeing, respiratory, sleep, audio levels and so much more.
Because of the Health app now correlating and ingesting so much information we can track where this information is coming from. First let's start with the file path of interest:
private/var/mobile/Library/Health/healthdb.sqlite*
If we open it in SQLite browser we see 40+ tables now. One table of interest is the "source_devices" table. Here we get entries for every hardware device that the Apple Health is pulling information from. You may think that's a lot of devices but this is also tracking software versioning so one device may have multiple entries if you are updating it (for instance iOS).