Cross save allows you to play the characters from one platform account on all your linked accounts. So say you've been playing D2 on XBox and want to play your XBox characters on PC. You can set up Cross Save and make your XBox account the Cross Save account. Then when you log in on PC you will be presented with your XBox characters. Cross save does not merge data between accounts, so if you had any PC characters or gear they would become dormant and all you'd see is what you see on your XBox when logging into that PC account. Also, keep in mind cross save is meant to be a one-time function, not something you turn on and off at will. If you disable cross save you will have a mandatory 90 day waiting period before you can re-enable it. Also, if you purchase silver on any linked account you will be restricted from disabling cross save for 90 days from the purchase date of the silver.