Storage networking connects servers to shared storage.
DAS: Direct Attached Storage. Physically connected to one server. Simple but not shared.
NAS: Network Attached Storage. File-level access over TCP/IP using NFS or SMB. Servers access files directly.
SAN: Storage Area Network. Block-level access over dedicated networks. Servers see storage as local disks.
Main difference: NAS shares files. SAN shares blocks. With NAS, the server handles file systems. With SAN, each server manages its own file system on raw blocks.