Thanks for the info. So I don't need to sign up for an account on Inara or EDDN? Just download, run and it'll freely share?
You'll need to sign up to INARA (for example) to take full advantage of EDMC.
As long as you're running EDMC you'll be supplying data but if it's linked to an INARA account then INARA can do stuff like keep track of what mat's you've got, tell you whether or not you've got enough mat's to complete mod's and keep track of where you are in-game so you can use it to find commodities, modules or contacts etc.
Main thing, though, is after you install EDMC you'll get a FDev browser window popping up, asking you if you want to give EDMC permission to access your account.
You'll need to confirm this so EDMC has access to your account.
If you create an INARA account (or any other similar website), it'll give you a big, long, API number which needs to be copied/pasted into EDMC.
Click file > settings and then add the data to the appropriate page; EDSM, Coriolis, INARA etc.