Saving your bookmarks or favorites to your computer is a quick way to access your favorite websites. If you reformat your computer or some other disaster strikes, you may loose all those important sites. Even if you access multiple computers or other devices, you won’t have the same bookmarks on each computer. A great way to ensure you have your content backed up is to use social bookmarking. By backing up your bookmarks or favorites to a social bookmarking site, like Delicious or Diigo, you will be able to access your saved information no matter what computer you are using. Synchronizing your bookmarks makes navigating the web much easier.
Learn about Social Bookmarks in Plain English: by CommonCraft