Storage Area Network (SAN) is a storage system that is best for block level data sharing of critical files between servers and storage devices at data centers. SAN is probably recommended for large scale computing needs. So, small scale industries with limited budget would not need it.
Network Attached Storage (NAS) is the most suggested one for consolidating storage systems from DAS. It offers file serving and sharing through a network and increases the performance. Having one in all storage system is the biggest plus point. NAS is the First rated choice for SMBs.
Cloud is a term referring to accessing computer, IT and Applications through Internet connectivity. It enables companies or individuals to compute resource, as a Virtual Machine, Storage or an application. Cloud computing services can be Private, Public or Hybrid.
A storage Snapshot marks data for reference at a specific time. It does not store/backup the data but defines where and how the data was stored/organized. Snapshots are usually created for data protection but are also used for testing application software and data mining.
SnapMirror is a feature that replicates data to a destination from a source when a relationship is established between them. The destination can be on the same filer or completely in other location.
SnapVault is a storage backup feature that backs up data stored on multiple systems to a Central, Secondary system as read-only copies, rapidly and efficiently.