The Enterprise Server Option provides ultimate licensing simplicity by consolidating two Backup Exec Options into one. Each Enterprise Server Option gives you unlimited access to the Backup Exec Advanced Disk-Based Backup Option and Backup Exec Central Admin Server Option (Backup Exec SAN Shared Storage Option is built into the Backup Exec Central Admin Server Option).
New License includes 12-Months of Essential Maintenance,
Version Upgrade Licenses are for customers who own previous versions of Symantec Backup Exec on which their maintenance has expired.
Renewal License (12-Month) is for customers wishing to renew the current maintenance on their licenses.