Intro to syncing in iTunes on PC
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, contacts and other info.
Do I have to sync?
If you have an 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.
Note: To sync content from your computer to iPod classic, iPod nano or iPod shuffle, use iTunes on Windows 10 or later.
If you have an iPhone, iPad or iPod touch: You only need to sync your device with iTunes if you want to do any of the following:
Add your iTunes playlists to your device (unless you subscribe to Apple Music or iTunes Match)
Add your own videos to your device
Add photos, contacts and calendars to your device (if you don’t use iCloud)
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 an iCloud account — use iCloud to make sure items like your photos, contacts 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 using Autofill.
Do I have to connect my device to my computer to sync?
No. If you have an iPhone, iPad or iPod touch with iOS 5 or later, you can sync your device wirelessly when your computer and device are connected to the same Wi-Fi network.
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 iPhone, iPad or iPod touch, but you can sync other types of content, such as movies.
What if I installed the Apple Music app or the Apple TV app on my Windows computer?
Install and open the Apple Devices app 
on your device to sync your content to your other devices. See the Apple Devices User Guide for Windows for more details.
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.