Network backup is any backup system where the data to be backed up traverses the network to reach the backup media.
Network backup typically requires a client-server software architecture. The backup server resides on a centralized server and the backup clients reside on every system to be backed up.
Advanced network backup systems can manage backup media which are also connected to the backup server via a network.
Network backup systems are much more scalable and manageable than local backup systems where tape drives are attached to each comouter ystem.
Because network backup systems can backup so many computers, they normally utilize tape autochangers to give them greater storage capacity.