NAS: NAS is essentially a dedicated appliance with a built-in file system to store the files and then present file shares to servers, applications and users. Most often we map to these systems using protocols such as SMB/CIFS (for Windows) or NFS (for Linux/Unix).
Unified Storage: Unified storage refers to a single logical system that is capable of presenting both dedicated LUNs (SAN) as well as folders within a file system (NAS)
