Syncing means adding items on your computer to a device. You can use iTunes to sync the items in your iTunes library to your device, as well as photos, books, contacts, and other info.
Do I have to sync?
If you have iPod classic, iPod nano, or iPod shuffle: You have to sync your device with iTunes. There’s no other way to add content to it.
If you have an iOS device (iPod touch, iPhone, or iPad): You only need to sync your device with iTunes if you want to:
Add your own videos to your device
Remove previously synced items from your device
If you prefer not to sync, you don’t have to: you can download items from the iTunes Store directly to your device, and—if you have a free iCloud account—use iCloud to make sure items like your photos, contact, and calendars are on both your computer and device.
Should I choose automatic or manual syncing?
Automatic syncing is the quickest and easiest option: it updates your device to match your iTunes library whenever you connect the device. You can select which items are automatically synced (for example, your entire library or just certain playlists). And you can still manually add most types of content to your device (including songs, movies, TV shows, and podcasts).
If you want to sync contacts, calendars, and photos to your device, you must sync them automatically.
Manual syncing lets you drag items to your device individually, which can take longer but gives you more control. You can still have podcast content sync automatically, even if you sync other items manually.
If you sync manually, you can also add a random selection of songs to your device by using Autofill.
Do I have to connect my device to my computer to sync?
What if I use Apple Music or iTunes Match?
If you subscribe to Apple Music or iTunes Match, you can’t use iTunes to sync music to your iOS device, but you can sync other types of content, such as movies and books. To find out how to add music and other items to your device from iCloud, see the documentation for your device.
What if I have more than one iTunes library?
If you choose manual syncing, you can sync iPod touch, iPod classic, iPod nano, and iPod shuffle with multiple iTunes libraries. You can sync iPhone and iPad with only one iTunes library at a time.
Note: If you subscribe to Apple Music, you can’t sync your saved Apple Music songs to a device.