EndNote Online is a cloud-based version of EndNote that can be used alongside (not instead of) EndNote desktop. You can use EndNote Online to sync your EndNote library between computers. This can be useful when you work with multiple computers that have EndNote downloaded, or if you need to access your references on a computer that does not have EndNote.
EndNote Online also allows you to share or work collaboratively with others:
In addition to EndNote Online, there is also a web-only interface for EndNote 21 called EndNote Web. As EndNote Web does not yet have the full range of sharing or advanced syncing features found in EndNote Online, we recommend using EndNote Online until EndNote Web is more fully developed. If you are unsure whether you are using EndNote Online or EndNote Web, check the URL:
To sync your EndNote library to your EndNote Online account:
Any changes you make to references will now sync between EndNote desktop and EndNote Online at 15 minute intervals.