vSphere® Data Protection is a backup and recovery solution designed for vSphere environments. Powered by EMC Avamar, it provides agent-less, image-level virtual machine backups to disk. It also provides application-aware protection for business-critical Microsoft applications (Exchange, SQL Server, SharePoint) along with WAN-efficient, encrypted backup data replication. vSphere Data Protection is fully integrated with vCenter Server and vSphere Web Client.

New features with VDP 5.5:
- Replication of backup data to EMC Avamar - move backup data offsite for disaster recovery purposes (backup data is de-duplicated at both the source and destination and only changed data segments are sent across the wire, bandwidth utilization is minimized)
- Direct-to-Host Emergency Restore - restore of a virtual machine directly to a host without the need for vCenter Server and the vSphere Web Client (e.g. use VDP to backup vCenter Server)
- Backup and restore of individual .vmdk files
- Granular scheduling for backup and replication jobs
- Flexible VDP storage management - when deploying VDP, separate data stores can be selected for the VDP guest OS and backup data partitions

Introduction to VDP here: http://www.vmware.com/files/pdf/techpaper/Introduction-to-Data-Protection.pdf