A LAN-free backup is a backup of server data to a shared, central storage device without sending the data over the local area network (LAN). It is usually achieved by using a storage area network (SAN).
Note that trivial backup to a dedicated, unshared storage device (such as local tape drive) does not meet the definition.
The goal of LAN-free backup is to reduce the load on LAN and reduce the time it takes to complete the backup. It offers an alternative way of backup than a simple data copy to network-attached storage (NAS) over LAN.
It comes in different flavours: