The synchronize view is useful if you want to see the overall status of your working copy against the state of the repository, including any updates. The view focuses on inbound and outbound changes, where inbound changes are the changes that others have committed and are coming in to your working copy when synchronizing. The outbound changes are the ones you did to your repository as a result of editing, removing or adding resources.
In short, the synchronize view offers a different way of updating and commiting your work, and does so in a manner which may be more familar to you as an Eclipse user.