Actually all I do is stream to my iPhone, Mac, iPad, Apple TV, and homePod. I don't store any music on any of my devices unless I am going to be traveling, and then I only download enough music to keep me entertained until I get to the next place that has WiFi and I can download more music without incurring any data charges at all. The one exception is my Apple Watch where I keep some music to accompany walking for health and relaxation. The rest, including music added from CDs or Vinyl, is all stored either on iCloud or Apple's music Library. (Actually there is very little stored on iCloud, to the best of my knowledge only one album, Dave Brubeck's oratorio Light In The Wilderness. Everything else I have uploaded has turned out to be in the Apple Library so instead of storing my upload a pointer to Apple's Library copy and a notation that I own that tune or album is stored. So far it has worked flawlessly for ME and MY needs. YMMV.
If you cancel our subscription, you will not be able to play the tunes you "subscribed to" but other than that, they are pretty much the same as those you upload from a CD or other media. The monthly plan is the most expensive option at $7.99/month.
