HT4759: iCloud: System requirementsLearn about iCloud: System requirements
Currently Being ModeratedMar 18, 2013 9:48 PM (in response to blyates88)
If you want to keep your contacts and other data you sync with iCloud separate, you'll have to create separate iCloud accounts, which will require different IDs. If you share the same iCloud account/ID on multiple devices, the synced data will be merged and will appear on all devices syncing with the shared account.
You can still share the same ID for iTunes; it doesn't have to be the same as the one used for iCloud.