In computer storage, NetApp filer, known also as NetApp Fabric-Attached Storage (FAS), or NetApp's network attached storage (NAS) device are NetApp's offering in the area of storage systems. A FAS functions in an enterprise-class storage area network (SAN) as well as a networked storage appliance. It can serve storage over a network using file-based protocols such as NFS, CIFS, FTP, TFTP, and HTTP.