Q: i cloud and i tune addresses

They can be different.

I think what you are referring to are AppleIDs.  What confuses many people is that when you create an AppleID, you enter one of your email addresses as the "username".  It's not just Apple that uses this horrible choice, nearly every popular cloud or social platform uses an email address as a username.

With that said, it's not uncommon to have more than one AppleID.  As a matter of fact, before the recent announcement of "Family Sharing" functionality, having one AppleID (username/email address) for the Apple Store (App Store/iTunes Store), and another for your personal iCloud and iMessages accounts was normal for the majority of families.  That way you can share your purchases using one account your keep your personal data and settings separate on another.

The other thing that is still not clear to many iOS and Mac OS users is that the following services all allow you to choose SEPARATE AppleIDs to login:

On iOS:

• Settings > iCloud
• Settings > Messages
• Settings > FaceTime
• Settings > iTunes & App Store

On Mac OS:

• System Preference > iCloud
• System Preferences > Internet Accounts
• System Preferences > App Store

So, it's perfectly allowable to use one AppleID for your iOS and Mac OS "Tunes & App Store" login, yet use another AppleID for your personal iCloud, Messages, and FaceTime settings.

Note that you would typically only do this if you have family members that share a Store account or if you accidentally have used several AppleIDs over the years.  Unfortunately there is no want to merge AppleIDs of this is the case.

I hope this information helps.