To synchronize data between devices, the devices must use a common communication medium. USB and Wi-Fi connections are the most common connection types used to synchronize data between devices.

Because most Android devices do not have a desktop program for performing data synchronization, most users use and sync with Google’s different web services, even when synchronizing with a desktop or laptop computer. One benefit of synchronizing data using this method is that the data is accessible from any computer or mobile device at any time by signing in to a Google account. The disadvantage to this arrangement is that it can be difficult to synchronize data with programs that are installed locally on a computer, such as Outlook for email, calendar, and contacts, or iTunes for music and video.

Before iOS 5, synchronization was limited to using a USB connection cable to connect the device to a computer. You can now use Wi-Fi Sync to synchronize with iTunes wirelessly. To use Wi-Fi Sync, you must first synchronize the iOS device with iTunes using a USB cable. You must also turn on Sync over Wi-Fi Connection in the Summary pane of iTunes. After that, you can use Wi-Fi Sync or a USB cable. When the iOS device is on the same wireless network as the computer running iTunes and it is plugged into a power source, it automatically synchronizes with iTunes.

Cross-Platform Data Synchronization

Often, a user has devices that run different operating systems. Synchronization of data between different operating systems is called cross-platform data synchronization. Third-party applications that handle Android synchronization between Outlook or iTunes must be installed for synchronization to work. iTunes can be installed on either a Windows or Apple computer, and an Android or iOS device can synchronize data with either one.

Apps can also be used to perform synchronization between different computing platforms. Dropbox is an example of an application that can be installed on different platforms and synchronize different types of data. One particularly useful feature is the ability to set photographs from a mobile device to automatically sync. When a picture is taken, it is automatically sent to a remote server. When another device, such as a tablet or desktop computer, is running the software, the photograph is automatically downloaded.