Syncing (or synchronization) means transferring data from your iPhone to your computer, or from your computer to your iPhone, so that the two data sets match. Most of the time, this goes as smoothly as you would expect for a well-designed product from Apple (which is what the iPhone is!). But, problems do occur.
In this section, I first cover the sync basics that are especially important for troubleshooting. Then, I explain how to deal with problems that can occur even if you know and follow all the basics.
(I cover ringtone syncing later, in Create and Sync Custom Ringtones.)
I don’t cover all the different options for determining which data is synced, such as choosing a group from Address Book to sync in Contacts ...