Storage area networks (SANs) and network attached storage (NAS) both provide networked storage solutions. A NAS is a single storage device that operates on data files, while a SAN is a local network of multiple devices. The differences between NAS and SAN can be seen when comparing their cabling and how they're connected to the system, as well as how other devices communicate with them. However, the two are sometimes used together to form what's known as a unified SAN.