An Adobe ID helps ensure that your eBooks (and other digital publications) are not locked onto one device - eBooks are assigned to you through your personal ID and can be viewed on any device that you authorise with that ID.
EBooks that you purchase or borrow from a library often contain digital rights management (DRM) protection that restricts the items from being shared with others. An Adobe ID is free but you will need to provide a name, country and email address when you register.
Where do I register?
To register go to http://www.adobe.com/au/products/digital-editions.html.
Click on “sign in” in the top right hand corner. Then click on the link that reads “Don’t have an Adobe ID?” to register.
And finally - don’t forget to make a note of your ID and password.