SAN provides block-level access to data, treating storage devices as though they were directly connected to the server.
NAS gives file-level access to data over a network.
SAN normally makes use of protocols like Fiber Channel for communication among storage devices and servers.
NAS uses standard network protocols such as NFS (Network File System) or SMB (Server Message Block) to provide file-level access.
SAN architectures are highly scalable, capable of supporting large amounts of storage and multiple servers.
NAS devices are also scalable, allowing additional storage capacity to be added easily to the existing network.
SANs are commonly used in environments where performance, reliability, and scalability are paramount.
NAS is well-suited for general file sharing, centralized storage, backup, and archiving purposes.