What is the difference between hierarchical storage management and storage area network technologies?

A.
HSM uses optical or tape jukeboxes, and SAN is a standard of how to develop and implement this technology.

B.
HSM and SAN are one and the same. The difference is in the implementation.

C.
HSM uses optical or tape jukeboxes, and SAN is a network of connected storage.

D.
SAN uses optical or tape jukeboxes, and HSM is a network of connected storage systems.

Explanation:
C: Hierarchical storage management (HSM) provides continuous online backup functionality. It combines hard disk technology with the cheaper and slower
optical or tape jukeboxes. The HSM system dynamically manages the storage and recovery of files, which are copied to storage media devices that vary in speed
and cost. The faster media hold the data that is accessed more often, and the seldom-used files are stored on the slower devices, or near-line devices. The
storage media could include optical disks, magnetic disks, and tapes. This functionality happens in the background without the knowledge of the user or any need
for user intervention. A storage area network, on the other hand, consists of large amounts of storage devices linked together by a high-speed private network and
storage-specific switches. When a user makes a request for a file, he does not need to know which server or tape drive to go tothe SAN software finds it and
provides it to the user.
+ A is incorrect because SAN is not a standard for how to develop and implement HSM. A SAN is a network of connected storage devices. SANs provide
redundancy, fault tolerance, reliability, and backups, and they allow the users and administrators to interact with the SAN as one virtual entity. Because the
network that carries the data in the SAN is separate from a company’s regular data network, all of this performance, reliability, and flexibility come, without impact
to the data networking capabilities of the systems on the network.
+ B is incorrect because HSM and SAN are not the same. Hierarchical storage management (HSM) uses conventional hard disk backup processes combined with
optical/tape jukeboxes. A storage area network (SAN) uses a networked system of storage devices integrated into an established network.
+ D is incorrect because the statement is backward. HSM uses optical or tape jukeboxes, and SAN is a network of connected storage systems. HSM was created
to save money and time. It provides an economical and efficient way of storing data by combining higher-speed, higher-cost storage media for frequently accessed
data with lower-speed, lower-cost media for infrequently accessed data. SANs, on the other hand, are for companies that have to keep track of terabytes of data
and have the funds for this type of technology. They are not commonly used in large or mid-sized companies.