The Free On-line Dictionary of Computing (30 December 2018):

Network Attached Storage

    (NAS) Fixed disks, RAID arrays, and
   magnetic tape drives connected directly to a Storage Area
   Network (SAN) or other direct network connection.  This is in
   contrast to a file server where the peripherals are
   connected to the network via a computer (the server).

   (2003-06-30)