If you backup your iPhone, iPad, or iPod touch using iTunes, you may find it useful to be able to check the status of these backups and when the last one was made for each of your devices. You can easily find this out by going into your iTunes Preferences and selecting the Devices section.
A list of all of your device backups will be shown here by device name, with the date and time of the last backup for each. If you have multiple backups under the same name, which can often happen if you’ve upgraded to a new device, you can easily tell which is which simply by hovering over them with your mouse pointer; a popup will appear displaying the serial number of the device from which that backup was made, along with the phone number and IMEI number in the case of an iPhone or cellular-capable iPad.
If you want to remove any old backups, simply select the one you want to remove and click the “Delete Backup” button. Although deleting a backup is ultimately irreversible, the good news is that it isn’t actually removed until you click “OK” to close the iTunes preferences dialog, so if you make a mistake, simply click “Cancel” instead, and the backup will be left alone.