iTunes Match

An annual subscription that allows you to access all your music—even songs imported from other sources and not purchased in the iTunes Store—and makes it available on up to 10 of your computers and devices.

To use iTunes Match, you need to turn on Sync Library on all the computers and devices where you want to use it. If you subscribe to Apple Music, you don’t need to subscribe to iTunes Match unless you still need to access your music on Apple TV (2nd or 3rd generation).

See the Apple Support article Subscribe to iTunes Match.