iTunes creates a backup of settings, app data, and other information on iPad when you:
Backups do not include synced items, such as music, videos, photos, or information such as contacts and calendars from your computer. Apps from the App Store are included in the first backup after the apps are downloaded. Subsequent backups include just the app data.
To restore all of your content, you must sync your iPad after restoring the backup information. If your iPad is set to sync automatically, synced items will be restored immediately after you restore or update the device.
Restoring from a backup is not the same as restoring iPad from the Summary page in iTunes. Restoring from a backup doesn’t reinstall iPad software. The backup restores data for apps, settings and other information.
To encrypt the backup with a password, select “Encrypt backups” on the summary page and enter a password.