iTunes Match uploads your music library from the Apple Music app on your Mac or iTunes for Windows on your PC. Then you can access your music library on all of your devices that have Sync Library turned on.

To subscribe to iTunes Match, update your Mac to the latest version of macOS. On your PC, make sure that you have the latest version of iTunes for Windows.

iTunes Match isn't a back up service, so make sure to always have a back up of your music collection before you make any changes.