How to ad another iPhone backup to my iTunes?

I have two iPhone's that need separate backups for an was wondering if I needed to make another account on my computer with iTunes or if there's a way to have two different backups on the same iTunes. Thanks in advance.

Added (1). How do I add another iPhone backup to my iTunes?

You can have as many as you want, as far as I know. I manually back up 2 ipads and and 2 iphones every once in awhile just cause. Never had an issue with it. The backups are all labeled per device, so I know which is which!