iPhone and iPod touch: Syncing and merging data

One-way Syncing (Unidirectional)

The iPhone and iPod touch will only sync certain content one-way (unidirectionally) from the computer (Mac OS or Windows) to the iPhone/iPod touch or from the device to the computer. For example, with audio/video content such as music, movies, TV shows, and podcasts the data will only sync from the computer to the device. You will not be able to modify this type of content from the iPhone/iPod touch. All changes will need to be made in iTunes or the computer that is syncing with the device. In a similar fashion, photos taken from the iPhone will only sync one-way from the device to the computer.

The one exception are Applications. Applications can be removed from the iPhone without connecting to iTunes. See Deleting Applications for more information.

Two-way Syncing (Bidirectional)

The iPhone/iPod touch is capable of two-way syncing (with merge capabilities) when dealing with other content such as Contacts, Calendars, and Bookmarks. For example, iTunes will copy and modify contacts made on the iPhone/iPod touch and contact manager such as Yahoo! Address Book, Outlook Contacts, Outlook Express, Google Contacts, or the Mac Address Book. When you sync the iPhone, iTunes checks for any changes to your contact information made from the iPhone/iPod touch or your contact manager and will warn you of possible conflicts or changes that affect a large number of your contacts before making those changes.

Content purchased from the iTunes Store or App Store are synced back to iTunes if they were purchased on the device.

Overview

Computer to iPhone/iPod touch (One-Way Sync)

• Audio/Video content
• Applications

iPhone to Computer (One-Way Sync)

• Photos taken by the iPhone camera

Computer to iPhone/iPod touch and vice-versa (Two-Way Syncing with merge capabilities)

• Contacts
• Calendars
• Bookmarks
• Notes

Purchased content syncing

• If purchased content is synced to your iPhone or iPod touch is not found on your computer the next time you sync, iTunes will offer to transfer these items back to your computer. Your computer must be authorized to use your iTunes Store account for this feature to work. See Syncing Purchased Applications and Syncing Purchased Content for more information.