Syncing is not the same as backing up. If your contacts are associated with iCloud, any changes you make to them will be reflected immediately among all of your similarly configured devices.
"Your iOS device backup only includes data and settings stored on your device. It doesn’t include data already stored in iCloud. That includes contacts, calendars, bookmarks, mail messages, notes, shared photo albums, iCloud Photo Library, My Photo Stream, and documents you store in iCloud Drive."
Quoted Source: https://support.apple.com/kb/PH12519?locale=en_US
10-07-2016 08:43 PM