A BlackBerry ID gives you convenient access to multiple BlackBerry products and services. After you create a BlackBerry ID, you can use your BlackBerry ID email address and password to log in to any BlackBerry product that supports BlackBerry ID. With BlackBerry ID, you can manage apps that you downloaded from the BlackBerry App World storefront and keep apps you downloaded when you switch smartphones.
You are prompted to log in using your BlackBerry ID when you set up a BlackBerry PlayBook tablet or a BlackBerry smartphone running BlackBerry 7. If you previously created a BlackBerry ID, you must use it when you set up your new tablet or smartphone (instead of creating a new BlackBerry ID). You can log in to both a tablet and a smartphone using the same BlackBerry ID.
If you're using an older BlackBerry smartphone, you might be able to create a BlackBerry ID from within an app that supports BlackBerry ID, or you can create a BlackBerry ID by visiting www.blackberry.com/blackberryid.