A data synchronization method, system, server and data synchronization terminal

The present invention discloses a data synchronization method, system, server and terminal data synchronization. Source summary information of digital content is determined by the synchronization server corresponding to the user to upload, determining information storing only briefly, or further stores storage location information of the digital content or digital content digital content according to the source itself, thereby reducing the traffic data backup simplified data migration difficult to replace the terminal user, reducing the cost of the user communications carrier network resources and pressure.