How can I keep my iPhone
I just got the iPhone X but have decided to keep my current iPhone 6sPlus. How can I do this?
Are you asking how you can keep both phones and share the applications and data between them? If so, you can backup your older phone and do a restore to the newer one. Also, just be sure that you sign into the same Apple ID on both phones so that their data can be synced with the same iCloud account.